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Area of a circle

Video vocabulary

just

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US / dʒʌst /

UK / dʒʌst /

A1
  • adjecitve
  • Proper or appropriate; as is deserved
  • Doing or being what is right or fair
  • Legally correct; having enough evidence
  • adverb
  • Almost; nearly
  • Exactly at the time of
  • Exactly (the same as, like)

ask

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US / ɑ:sk /

UK / æsk /

A1
  • verb
  • To say to someone that you want something

piece

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US / pi:s /

UK / pis /

A1
  • noun
  • A counter in a board game
  • Small part of something larger
  • verb
  • To put items together to assemble something

well

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US / wel /

UK / wɛl /

A1
  • adjecitve
  • Being in a fortunate, good condition or state
  • Healthy and in good condition
  • adverb
  • In an acceptable, proper, or successful manner
  • In a complete, total, or full manner
  • A great and considerable degree
  • In a successful way, in a good or satisfactory way
  • exclamation
  • Used to begin or continue a particular statement
  • Used to show you want to start saying something
  • Used to express that you are waiting for a reply
  • You say this to change the topic of a conversation
  • Used to indicate you are making a final remark
  • noun
  • Long deep hole in the ground to get water
  • verb
  • To cause your eyes to fill with tears

equation

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US / ɪˈkweɪʒn /

UK / ɪˈkweʒən, -ʃən /

B1
  • noun
  • Mathematical statement showing things to be equal
  • Complex set of different facts, ideas or issues

question

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US / 'kwestʃən /

UK / ˈkwɛstʃən /

A1
  • noun
  • Issue or problems you are dealing with
  • What you ask about; issue
  • verb
  • To ask for or try to get information
  • To have or express concerns or uncertainty

fact

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US / fækt /

UK / fækt /

A1
  • noun
  • Something that is known or proved to be true

much

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US / mʌtʃ /

UK / mʌtʃ /

A1
  • adjecitve
  • Very; to a high level or degree
  • adverb
  • A lot; large amount; a high degree of
  • Nearly; basically
  • On many occasions; often
  • noun
  • A large amount; a great quantity

positive

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US / ˈpɒzətɪv /

UK / ˈpɑzɪtɪv /

A2
  • adjecitve
  • Showing agreement or support for something
  • Being sure about something; knowing the truth
  • Having the charge produced by electrons
  • Being good or useful
  • Showing that a chemical is present in a test

computer

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US / kəmˈpju:tə(r) /

UK / kəmˈpjutɚ /

A1
  • noun
  • Machine for storing data, accessing the internet

define

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US / dɪ'faɪn /

UK / dɪˈfaɪn /

A2
  • verb
  • To explain the meaning of words
  • To set or mark the limits of something

those

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US / ðəʊz /

UK / ðoz /

A1
  • determiner
  • The people or things we are talking about
  • pronoun
  • The objects far from the speaker

delve

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US / delv /

UK / delv /

C1
  • verb
  • To search, especially as if by digging, in order to find a thing or information

compound

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US / 'kɒmpaʊnd /

UK / kɑmˈpaUnd /

B1
  • adjecitve
  • (Of a term) created by combining two or more words
  • noun
  • Series of buildings that are walled or fenced off
  • Chemical made up of several others
  • Closed walled area, as in a prison
  • Something formed by combining elements/parts
  • Term created by using two or more words together
  • verb
  • To pay interest on a loan including the interest
  • To make something from various parts or components
  • To make a mistake or problem worse

for

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US / fə(r) /

UK / fɔr,fə /

A1
  • preposition
  • Used to show the purpose, or need of something

time

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US / taɪm /

UK / taɪm /

A1
  • noun
  • Speed at which music is played; tempo
  • Point as shown on a clock, e.g. 3 p.m
  • Number of hours, minutes needed to do something
  • Occasion when something happens
  • Period or occasion that something occurred
  • Period in history or the past
  • Something measured in minutes, hours, days, etc.
  • How long an event takes; duration
  • verb
  • To check speed at which music is performed
  • To choose a specific moment to do something
  • To measure how long an event takes, e.g. a race
  • To schedule something to occur at a specific moment

anyway

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US / ˈeniweɪ /

UK / ˈɛniˌwe /

A1
  • adverb
  • A word used to change the topic of a conversation

screen

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US / skri:n /

UK / skrin /

A2
  • noun
  • Wire net in a door or window to keep insects out
  • Displays in a theater on which movies are shown
  • Flat surface on a computer or TV showing images
  • verb
  • To hide or block something from being seen
  • To examine to find something, e.g. best candidate

another

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US / əˈnʌðə(r) /

UK / əˈnʌðɚ /

A1
  • adjecitve
  • One more, but not this
  • determiner
  • One more added
  • pronoun
  • One more (thing)

hey

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US / heɪ /

UK / he /

A1
  • exclamation
  • What you say when you want someone's attention

leave

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US / li:v /

UK / liv /

A1
  • noun
  • Permission to do something
  • Vacation time; time off work
  • verb
  • To go away from; depart
  • To gift property to someone after you die
  • To allow something to continue happening
  • To let something remain unused or available
  • To let something or someone remain somewhere

and

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US / ənd /

UK / ənd, ən,ænd /

A1
  • conjunction
  • Used to refer to two or more things
  • Plus; in addition; on top of that
  • Used to introduce an action that follows another

distance

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US / 'dɪstəns /

UK / ˈdɪstəns /

A2
  • noun
  • Lack of friendliness toward another person
  • Amount of space between two places or things
  • verb
  • To make it clear that you are not involved

think

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US / θɪŋk /

UK / θɪŋk /

A1
  • verb
  • To have an idea about something without certainty
  • To have an idea, opinion or belief about something

normally

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US / ˈnɔ:məli /

UK / ˈnɔːrməli /

B1
  • adverb
  • In the manner that is usual or ordinary

deeply

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US / ˈdi:pli /

UK / ˈdiplɪ /

A2
  • adverb
  • To a significant degree
  • To a great, intense or extreme extent

out

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US / aʊt /

UK / aʊt /

A1
  • adverb
  • No longer stylish (e.g. fashion)
  • Away from home, business, or the usual place
  • In a direction/movement away from inside or center
  • noun
  • Act when a batter cannot continue playing
  • verb
  • To tell people a secret

over

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US / 'əʊvə(r) /

UK / ˈovɚ /

A1
  • adverb
  • Finished; no longer happening
  • Towards the ground/away from a standing position
  • noun
  • A set of six consecutive balls bowled in cricket
  • other
  • Finished
  • preposition
  • Showing the relation when a thing is above another
  • On or covering something
  • Above or across something
  • More than you need
  • From one side to the other
  • In the direction of; toward

keep

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US / ki:p /

UK / kip /

A1
  • noun
  • Large, strong tower in the middle of a castle
  • Money spent on you so you can live in a place
  • verb
  • To continue doing something; not to stop
  • To stop balls going in a goal in sports
  • To not give back or return something
  • (Of food) to not spoil or not rot
  • To take possession of something to own, e.g. a pet
  • To have and continue to hold something
  • To do something that you have promised or agreed
  • To stay in a certain place or condition
  • To maintain the rules

radius

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US / ˈreɪdiəs /

UK / ˈrediəs /

B2
  • noun
  • Area around a certain point
  • Long bone on the thumb side of your lower arm
  • Line from the center to the edge of a circle

something

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US / ˈsʌmθɪŋ /

UK / ˈsʌmθɪŋ /

A1
  • adverb
  • In some degree or measure
  • noun
  • a person or thing of some value or consequence
  • pronoun
  • Thing that is not yet known or named
  • Approximately

entire

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US / ɪn'taɪə(r) /

UK / ɛnˈtaɪr /

A2
  • adjecitve
  • Complete or full; with no part left out; whole

into

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US / 'ɪntə /

UK / ˈɪntu /

A1
  • preposition
  • Moving or going inside something
  • In the same direction as; in the direction of
  • So as to become; taking the state of

lucky

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US / 'lʌkɪ /

UK / ˈlʌki /

A1
  • adjecitve
  • Fortunate; having good things happen by chance

other

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US / 'ʌðə(r) /

UK / ˈʌðər /

A1
  • adjecitve
  • A thing different from that mentioned
  • determiner
  • (Something) else; not the first (one)
  • pronoun
  • Being the one and only thing of that category

perfect

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US / 'pɜ:fɪkt /

UK / ˈpɚfɪkt /

A1
  • adjecitve
  • So good it cannot be improved
  • verb
  • To do something so well, it cannot be done better

one

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US / wʌn /

UK / wʌn /

A1
  • pronoun
  • You; we; people in general; someone
  • The thing or person previously referred to
  • adjecitve
  • Used to refer to people generally
  • Being a strong example of (something mentioned)
  • number
  • Number 1

root

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US / ru:t /

UK / rut, rʊt /

A2
  • noun
  • Emotional connection with a place, history etc.
  • The origin or starting place of something
  • A number that is multiplied by itself
  • Part of plant growing underground, as to get water
  • Part of tooth, hair etc. from which the rest grows
  • Base part of a word to which affixes can be added
  • verb
  • To cause a plant to develop or grow roots
  • (Animals) to search for e.g. food in earth
  • To stop someone moving, as through fear

play

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US / pleɪ /

UK / pleɪ /

A1
  • noun
  • Loose, free movement between two objects
  • Single action in a sports game
  • Performance in which people act in a theater
  • verb
  • To act as a character in a movie, or on stage
  • To perform music on an instrument
  • To use a device, e.g. a video game
  • To do something for enjoyment and fun
  • To do or perform a game or sport

this

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US / ðɪs /

UK / ðɪs /

A1
  • adjecitve
  • Used to indicate something already been discussed
  • Used to indicate something happening around now
  • adverb
  • An indication by a physical motion or gesture
  • A specific amount of
  • determiner
  • Person, thing, or idea near you
  • pronoun
  • Person, thing that has already been discussed

circular

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US / ˈsɜ:kjələ(r) /

UK / ˈsɜ:rkjələ(r) /

B2
  • adjecitve
  • Shaped like a circle or part of a circle
  • noun
  • Paper with news, ads, etc. sent round to people

also

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US / 'ɔ:lsəʊ /

UK / ˈɔlso /

A1
  • adverb
  • In addition; too; in a similar way

cube

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US / kju:b /

UK / kjub /

B2
  • noun
  • Solid object that has six square sides
  • verb
  • To cut food into the shape of small cubes
  • To multiply a number by itself three times

live

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US / lɪv /

UK / liv /

A1
  • adjecitve
  • Being broadcast as events happen, not recorded
  • Carrying electric current; able to give a shock
  • Glowing because burning; hot
  • Not yet killed (for food)
  • adverb
  • (Music, drama) as it is performed
  • verb
  • To be alive
  • To experience a particular type of life
  • To make your home in a house or town

how

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US / haʊ /

UK / haʊ /

A1
  • adjecitve
  • To what degree? in what amount?
  • adverb
  • (Used to explain the way to do something)
  • exclamation
  • For what purpose or reason?
  • (Used to ask someone or something's condition)

kind

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US / kaɪnd /

UK / kaɪnd /

A1
  • adjecitve
  • In a caring and helpful manner
  • friendly and considerate
  • noun
  • One type of thing

you

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US / jʊ /

UK / ju /

A1
  • pronoun
  • Person someone is speaking or writing to
  • Person or people in general

let

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US / let /

UK / lɛt /

A1
  • verb
  • To allow someone to do something
  • Introducing a suggestion to do something together
  • To rent a house, etc. to others

the

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US / ðə /

UK / ðə /

A1
  • article
  • Used to refer to something already mentioned
  • Used to show there is only one of something
  • determiner
  • Used to describe all of a family

make

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US / meɪk /

UK / mek /

A1
  • noun
  • Product made by a particular company; brand
  • verb
  • To arrange or prepare something e.g. dinner
  • To get to (a place) on time
  • To gain the status of (teacher, lawyer, etc.)
  • To create something by putting things together
  • To earn a certain amount of money at a job
  • To cause or force a person to do something
  • To cause something to happen or be formed

answer

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US / 'ɑ:nsə(r) /

UK / ˈænsɚ /

A1
  • noun
  • Reply to a question someone asks
  • Solution to a problem or test question
  • verb
  • To reply to a question someone asks
  • To solve a test question or a problem

carpeting

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US / ˈkɑ:pɪtɪŋ /

UK / ˈkɑ:rpɪtɪŋ /

B1
  • verb
  • To cover a surface with, e.g. many flowers

imagination

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US / ɪˌmædʒɪˈneɪʃn /

UK / ɪˌmædʒəˈneʃən /

A2
  • noun
  • Ability to creates new ideas and mental images

able

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US / 'eɪbl /

UK / ˈebəl /

A2
  • adjecitve
  • Skilled; good at something
  • Having the ability to do something

surface

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US / 'sɜ:fɪs /

UK / ˈsɚfəs /

A2
  • adjecitve
  • Of the top layer; not deep or meaningful
  • noun
  • Top layer of the ground or of water
  • Nature or emotions that show, but may not be true
  • Outside or upper layer of something
  • verb
  • To give (road) a top layer
  • To appear after being hidden, unseen, or unknown
  • To come to the top of something; emerge
  • To come to the top level of water, mud, etc.

convention

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US / kənˈvenʃn /

UK / kənˈvɛnʃən /

A2
  • adjecitve
  • Concerning a large formal assembly or meeting
  • noun
  • Official agreement between two or more countries
  • Large formal assembly, e.g. to make laws
  • Proper and widely accepted way of behaving

someone

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US / ˈsʌmwʌn /

UK / ˈsʌmˌwʌn, -wən /

A1
  • pronoun
  • Person who is not known or named

here

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US / hɪə(r) /

UK / hɪr /

A1
  • adverb
  • In this place; at this location, position or time

always

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US / 'ɔ:lweɪz /

UK / ˈɔlwez,-wɪz,-wiz /

A1
  • adverb
  • For a very long time
  • At all times; in every situation
  • For ever

guess

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US / ɡes /

UK / ɡɛs /

A1
  • noun
  • Answer given when you don't know if it is correct
  • verb
  • To give an answer without knowing if it is correct

itself

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US / ɪtˈself /

UK / ɪtˈsɛlf /

A1
  • pronoun
  • Referring to it

thousand

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US / ˈθaʊznd /

UK / ˈθaʊzənd /

A1
  • number
  • Number 1,000

will

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US / wɪl /

UK / wɪl /

A1
  • noun
  • Desire or choice of someone
  • Document saying who gets your money when you die
  • Strong desire to do something; determination
  • Desire to do something; strong wish to do
  • other
  • Used with verbs to express the future
  • verb
  • To leave property to someone after your death
  • To use mental effort to make something happen
  • Am (is, are) likely to do
  • To influence someone to do something
  • To make something happen by strongly wanting it

day

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US / deɪ /

UK / de /

A1
  • noun
  • A period of 24 hours beginning at midnight
  • The period of time when it is light outside
  • Person's name

point

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US / pɔɪnt /

UK / pɔɪnt /

A1
  • noun
  • An item to be discussed
  • Small spot or dot
  • Fact or detail
  • Feature of something
  • The size of the text on a page or screen
  • A certain time or stage in a process
  • Certain position in time or space
  • Idea or fact you try to convince people about
  • Measurement of scores in a game, sport
  • Sharp end of something, e.g. a pen or pin
  • verb
  • To face a certain direction, e.g. north
  • To indicate something with your finger to others

area

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US / 'eərɪə /

UK / ˈɛriə /

A1
  • noun
  • Amount of measured space
  • A specific section or space; part of a region
  • A subject or field of study

fairly

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US / 'feəlɪ /

UK / ˈfɛrli /

A2
  • adverb
  • Quite; pretty; between very and a little
  • In a manner that is right and acceptable

past

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US / pɑ:st /

UK / pæst /

A2
  • adjecitve
  • No longer current or new
  • adverb
  • So as to go beyond, or further than something
  • noun
  • Time that existed before now, e.g. long ago
  • preposition
  • After a particular time
  • At a later point in distance; beyond

side

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US / saɪd /

UK / saɪd /

A1
  • adjecitve
  • In addition to the central or most important thing
  • Next to, or very close to, the right or left of
  • noun
  • Position or opinion that is opposite to another
  • Right or left part of a person's body
  • Feature of someone's personality
  • Straight edge of an object
  • One of two or more groups fighting each other
  • verb
  • To decide to agree with one point, not the other

too

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US / tu: /

UK / tu /

A1
  • adverb
  • In addition, also; with emphasis
  • Say that something is more than you want

divide

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US / dɪ'vaɪd /

UK / dɪˈvaɪd /

A2
  • verb
  • To split numbers by another number, e.g. 6 / 2 = 3
  • To separate something into equal pieces

imagine

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US / ɪ'mædʒɪn /

UK / ɪˈmædʒɪn /

A1
  • verb
  • To think creatively about; form mental picture of

probably

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US / ˈprɒbəbli /

UK / ˈprɑbəbli /

A1
  • adverb
  • That is likely to happen or be true

should

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US / ʃʊd /

UK / ʃʊd /

A1
  • other
  • Used to indicate what is proper or reasonable

actually

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US / ˈæktʃuəli /

UK / ˈæktʃuəli /

A1
  • adverb
  • Used to add new (often different) information

use

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US / ju:s /

UK / ju:s /

A1
  • noun
  • Ability to employ something
  • Need to enable it to work
  • Permission to do something with something
  • Act of spending money
  • Operation of a machine for its function
  • verb
  • To have; to eat, drink, consume etc.
  • To need to operate or work
  • To operate a machine, e.g. a computer
  • To treat a person badly
  • To do something with, for a task or purpose

write

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US / raɪt /

UK / raɪt /

A1
  • verb
  • To compose letters and words on paper or a screen
  • To invent or create a computer program
  • To create a song or piece of music

can

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US / kæn /

UK / kən,kæn /

A1
  • noun
  • A metal container for storing food
  • other
  • Able to; have the skill to; have the time to
  • verb
  • To have permission to
  • To be possible to do
  • To preserve food by sealing it in a metal container

alternate

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US / ɔ:lˈtɜ:nət /

UK / ˈɔ:ltərnət /

B2
  • verb
  • To follow one thing after another repeatedly

maybe

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US / ˈmeɪbi /

UK / ˈmebi /

A1
  • adverb
  • Possibly but not certainly; perhaps

our

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US / 'aʊə(r) /

UK / aʊr /

A1
  • determiner
  • Belonging to us

not

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US / nɒt /

UK / nɑt /

A1
  • adverb
  • Word indicating the negative
  • (Used to form the negative of verbs)

whole

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US / həul /

UK / hol /

A1
  • adjecitve
  • Complete or full; all of
  • Being in a good condition
  • noun
  • Complete amount or sum; total

want

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US / wɔnt /

UK / wɑnt, wɔnt /

A1
  • noun
  • Something you desire or wish for
  • State or condition of poverty
  • verb
  • To desire or wish for something; hope for a thing

video

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US / 'vɪdɪəʊ /

UK / ˈvɪdiˌo /

A2
  • adjecitve
  • Of a moving film, with sound
  • noun
  • Recording capturing action with sound
  • verb
  • To make a moving film of, with sound

deal

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US / di:l /

UK / dil /

A1
  • verb
  • To cope with something - usually troubles
  • To give (something bad e.g. news) to
  • To buy and sell illegal drugs
  • To give out (cards, etc.) to; distribute
  • To do business with someone or to sell products

equal

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US / 'i:kwəl /

UK / ˈikwəl /

A1
  • adjecitve
  • Same in shape, size, or number
  • verb
  • To add up or be the same as

formula

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US / 'fɔ:mjələ /

UK / ˈfɔrmjələ /

A2
  • noun
  • A mathematical or scientific rule
  • Plan, rule or method for doing or making something

measure

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US / ˈmeʒə(r) /

UK / ˈmɛʒɚ /

A1
  • noun
  • Plan to achieve a desired result
  • Tool used to calculate the size of something
  • verb
  • To determine the value or importance of something
  • To calculate size, weight or temperature of

now

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US / naʊ /

UK / naʊ /

A1
  • adverb
  • At the present time or moment
  • Right away or in the next possible moment
  • Used to refer to something that just happened
  • Time between the present and a moment in the past
  • conjunction
  • Resulting from or because of something

sense

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US / sens /

UK / sɛns /

A1
  • noun
  • Certain mental feeling or emotion
  • Normal or clear state of mind
  • Meaning of a particular word, phrase or text
  • verb
  • To perceive using sight, sound, taste touch etc.
  • To recognize the presence of something

apply

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US / ə'plaɪ /

UK / əˈplaɪ /

A1
  • verb
  • To spread a substance or liquid over a surface
  • To commit your time and effort to doing something
  • To make something useful in a certain situation
  • To be relevant for a situation
  • To ask formally for (job, permission etc.)

but

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US / bət /

UK / bʌt,bət /

A1
  • conjunction
  • Used before you say something different, opposite

good

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US / ɡʊd /

UK / ɡʊd /

A1
  • adjecitve
  • Proper, appropriate or right
  • (Of an amount) enough; plenty
  • Excellent; high quality
  • Acting well or properly; of moral character
  • In a positive or happy emotional state
  • noun
  • Advantage or benefit

give

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US / ɡɪv /

UK / ɡɪv /

A1
  • noun
  • Degree of flexibility in something, a material
  • verb
  • To hand over or present something to someone
  • To cause someone to have or experience something

become

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US / bɪ'kʌm /

UK / bɪˈkʌm /

A1
  • verb
  • To begin to be; grow to be; develop into
  • To be suitable for a particular job or role

same

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US / seɪm /

UK / sem /

A1
  • adjecitve
  • Being equal in quality and amount
  • Identical; not different
  • Not changing; constant

would

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US / wʊd /

UK / wʊd /

A1
  • other
  • Used to indicate something imagined
  • Used to ask or request something politely
  • Verb used to indicate possibility, request etc.
  • Used to indicate a preference
  • Used to indicate a reaction
  • Indicates something that occurred repeatedly
  • Used to indicate willingness or ability to do

both

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US / bəuθ /

UK / boθ /

A1
  • determiner
  • Used to refer to two things at the same time
  • pronoun
  • Used to refer to two things at the same time

initial

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US / ɪ'nɪʃl /

UK / ɪˈnɪʃəl /

A2
  • adjecitve
  • Existing or occurring at the beginning
  • noun
  • First letter of your given name
  • verb
  • To authorize something by writing your initials

simple

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US / 'sɪmpl /

UK / ˈsɪmpəl /

A1
  • adjecitve
  • Not hard to understand or do; not complex
  • Having only a few parts; not complex
  • Being ordinary or normal
  • Being plain; without a lot added for style

space

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US / speɪs /

UK / spes /

A1
  • noun
  • Empty area kept for a specific reason, like a car
  • Empty area with nothing in it
  • Area in the sky where the stars are
  • Area between written words on a page
  • verb
  • To make a certain distance or time between

fill

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US / fɪl /

UK / fɪl /

A1
  • noun
  • Act of filling; amount used to make something full
  • verb
  • To make something full
  • To move into all parts of an area
  • To repair a surface by adding a substance to it
  • To use (time); to do something during

prove

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US / pru:v /

UK / pruv /

A2
  • verb
  • To demonstrate truth by providing evidence

work

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US / wɜ:k /

UK / wɚk /

A1
  • adjecitve
  • Activity completed in order to make money
  • noun
  • The product of some artistic or literary endeavor
  • Everything created by an author, artist, musician
  • Activity you do in order to make money
  • Place of employment
  • Final product or result of a some labor or effort
  • verb
  • To bring into a specific state of success
  • To be functioning properly, e.g. a car
  • To do your job in your company or workplace
  • To make an effort to do something
  • To operate a machine or device

list

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US / lɪst /

UK / lɪst /

A1
  • noun
  • Lean of a boat to one side
  • Series of written names, words or numbers
  • verb
  • To lean to one side, like a boat or ship
  • To present for sale for a specific price
  • To write a series of names, words, or numbers

pretty

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US / 'prɪtɪ /

UK / ˈprɪti /

A1
  • adjecitve
  • Being attractive to the eye in a simple way
  • adverb
  • Very; to a great degree

paper

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US / ˈpeɪpə(r) /

UK / ˈpeɪpər /

A1
  • adjecitve
  • Not existing in reality, or done infrequently
  • Made from the material that we use to make books
  • noun
  • Academic writing or a talk on a specific topic
  • Written test
  • Newspaper
  • Pages of a book are made from this

figure

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US / ˈfiɡə /

UK / ˈfɪɡjɚ /

A1
  • noun
  • Your body shape
  • Numbers in a calculation
  • Doll-like thing meant to represent a person
  • Picture or diagram giving information in a text
  • Person who is very important or famous
  • Shape of a person seen indistinctly or in outline
  • Amount that is expressed in numbers
  • verb
  • To appear in a game, play or event
  • To calculate how much something will cost
  • To understand after thinking; work out

way

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US / weɪ /

UK / we /

A1
  • adverb
  • Used to emphasize the amount of something
  • noun
  • Particular aspect of something being thought about
  • One of various choices that could be made
  • Particular existing condition or state
  • (Often long) distance or length of time
  • How something is done
  • Route to go to a place
  • Small street
  • Usual behavior, emotions or habits of someone

all

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US / ɔ:l /

UK / ɔl /

A1
  • adverb
  • Completely; totally
  • determiner
  • Being every one of something
  • pronoun
  • 100% of something; the complete amount

its

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US / ɪts /

UK / ɪts /

A1
  • adjecitve
  • Referring to or belonging to ‘it’
  • determiner
  • Of something; belonging or related to something
  • other
  • Possessive form of “it”

take

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US / teɪk /

UK / tek /

A1
  • noun
  • Filming of a single scene for TV or the movies
  • verb
  • To accept something that is offered
  • To use a method of traveling, e.g. a bus or train
  • To use a camera to make (a photo)
  • To pick up something and go away with it
  • To study a subject in school
  • To attempt to pass (an exam)
  • To require a certain amount of time, money, space

room

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US / ru:m /

UK / rum, rʊm /

A1
  • noun
  • All of the people inside a particular room
  • Part of building enclosed by walls, e.g. kitchen
  • Opportunity to exist, happen, or be true
  • verb
  • To share a home with someone

between

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US / bɪˈtwi:n /

UK / bɪˈtwin /

A1
  • preposition
  • From one person, thing, or place, to another
  • In the space that separates two objects
  • Among two or more people who share something

everything

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US / 'evrɪθɪŋ /

UK / ˈɛvriˌθɪŋ /

A1
  • pronoun
  • All of the things mentioned

they

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US / ðeɪ /

UK / ðe /

A1
  • pronoun
  • Two or more people, animals, or things

very

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US / 'verɪ /

UK / ˈvɛri /

A1
  • adjecitve
  • Concerning a large degree or amount
  • adverb
  • A lot; much; many
  • Used to stress or emphasize a noun

cancel

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US / 'kænsl /

UK / ˈkænsəl /

A2
  • verb
  • To end a legal, business, or other agreement
  • To stop a planned event from happening

look

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US / lʊk /

UK / lʊk /

A1
  • noun
  • Person's beauty or physical attractiveness
  • Particular style of dress, clothes, or appearance
  • The way someone, something appears to be
  • Act of searching for or examining something
  • verb
  • To appear to be; seem

multiply

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US / ˈmʌltɪplaɪ /

UK / ˈmʌltəˌplaɪ /

B1
  • verb
  • To increase in number by reproducing/having babies
  • To increase something by a large quantity
  • To have increased by a large quantity
  • To calculate two numbers e.g. 2 x 4

rewrite

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US / ˌri:'raɪt /

UK / riˈraɪt /

A2
  • verb
  • To write again to improve, or correct errors

could

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US / kəd /

UK / kʊd /

A1
  • other
  • Past form of 'can' to mean have ability
  • Used to ask for something politely, or to offer

know

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US / nəʊ /

UK / noʊ /

A1
  • verb
  • To be familiar with a person or place, thing
  • To feel sure or be convinced about something
  • To discover or be aware of something
  • To be able to distinguish
  • To have knowledge of things

slightly

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US / ˈslaɪtli /

UK / ˈslaɪtli /

B1
  • adverb
  • Only a little

circumference

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US / səˈkʌmfərəns /

UK / sərˈkʌmfərəns /

C1
  • noun
  • Length around an outer boundary, e.g. a circle

have

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US / həv /

UK / hæv /

A1
  • verb
  • To drink, smoke, eat or use something
  • To experience the effects of something
  • To organize an event, or join in an activity
  • To own, possess, or hold something
  • To cause to happen or produce a particular effect

last

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US / lɑ:st /

UK / læst /

A1
  • adjecitve
  • Most recent; the latest
  • The one before
  • adverb
  • Final; with nothing following; after all others
  • Most recent; the latest
  • determiner
  • The one at the end
  • verb
  • To remain or continue for a certain period of time

diameter

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US / daɪˈæmɪtə(r) /

UK / daɪˈæmɪtɚ /

B1
  • noun
  • Distance across the center of an object

negative

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US / 'neɡətɪv /

UK / ˈnɛɡətɪv /

A2
  • adjecitve
  • Being harmful, unwanted or unhelpful
  • In mathematics, being less than zero
  • Focusing on the bad aspects; pessimistic
  • noun
  • The opposite to a positive electrical charge
  • In grammar, containing words such as 'no' or 'not'
  • Reply to a question or statement that means 'no'
  • Image on camera film used to make a photo

see

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US / si: /

UK / si /

A1
  • verb
  • To go on a date with someone
  • To predict whether something is, or will be true
  • To understand what someone says
  • To use your eyes to look at something
  • To visit a place often for sightseeing or pleasure
  • To visit or meet with someone
  • To find out by waiting or looking
  • To watch (a game, movie or TV show)

exposure

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US / ɪk'spəʊʒə(r) /

UK / ɪkˈspoʒɚ /

A2
  • noun
  • Allowing light through a cameras lens onto film
  • Being talked about in the media
  • Act of making something that is secret known
  • Experience of something directly

with

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US / wɪð /

UK / wɪð, wɪθ /

A1
  • preposition
  • As an employee of a certain company
  • Against something or someone
  • By using something as a means
  • Due to; because of
  • Including
  • Possessing as a feature
  • Related to
  • (Of the manner/attitude by which you do something)
  • Used to express that people or things are together

ratio

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US / ˈreɪʃiəʊ /

UK / ˈreɪʃioʊ /

C2
  • noun
  • The relationship in relative size, etc.

remember

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US / rɪ'membə(r) /

UK / rɪˈmɛmbɚ /

A1
  • verb
  • To give someone a gift, e.g. birthday, wedding
  • To hold a thought in your mind to not forget it
  • To bring a previous image or idea to your mind

conventional

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US / kən'venʃənl /

UK / kənˈvɛnʃənəl /

B2
  • adjecitve
  • Following the common attitudes and practices

next

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US / nekst /

UK / nɛkst /

A1
  • adverb
  • The one that follows another in time or order
  • At a time or place directly after the present one
  • noun
  • The one that follows after
  • adjecitve
  • Immediately after the previous one
  • First occurrence after the present one

problem

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US / ˈprɒbləm /

UK / ˈprɑbləm /

A1
  • adjecitve
  • Causing trouble
  • noun
  • Something difficult to deal with or causes trouble
  • Question to show understanding of a math concept

meter

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US / ˈmi:tə(r) /

UK / ˈmitɚ /

A1
  • noun
  • Unit of length equal to 100 cm or about 39 inches
  • Device for measuring things e.g. gas
  • Device to put money into to rent a parking place
  • Rhythm of a poem
  • verb
  • To measure water, etc. when it has to be paid for

unit

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US / ˈju:nɪt /

UK / ˈjunɪt /

B2
  • noun
  • One apartment in a building
  • Group of people, e.g. soldiers, that work together
  • A chapter of a textbook
  • A standard of measurement of something
  • Single item made by a company

world

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US / wɜ:ld /

UK / wɜrld /

A1
  • noun
  • All the humans, events, activities on the earth
  • Political division due to some kind of similarity

least

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US / li:st /

UK / list /

A1
  • adverb
  • In the smallest or lowest way
  • noun
  • Something that is of the lowest or smallest degree

right

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US / raɪt /

UK / raɪt /

A1
  • adjecitve
  • Correct or true
  • The south side of you looking at the rising sun
  • adverb
  • Exactly in a place or time
  • Being appropriate for a particular event
  • In a straight or direct manner
  • noun
  • Something you are legally or morally allowed to do
  • Ideal of what is just and good
  • Political view based on conservatism
  • verb
  • To fix something previously wrong or unjust
  • To make upright, as a boat that has turned over

then

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US / ðen /

UK / ðɛn /

A1
  • adverb
  • A time that is not now
  • Following another thing in time or arrangement
  • Following on reasonably from what was just stated
  • At that time, not now

number

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US / ˈnʌmbə(r) /

UK / ˈnʌmbɚ /

A1
  • noun
  • Symbols such as 1, 2, 56, 793
  • Particular song or dance performed during a show
  • Total quantity or amount of things
  • verb
  • To put numbers on things
  • To assign a sequence within a group, series, set
  • To claim to be part of a larger group, series, set

square

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US / skweə(r) /

UK / skwɛr /

A2
  • adjecitve
  • Being fair or honest
  • Multiply a number by itself e.g. 2x2 or 6x6
  • noun
  • Shape with 4 equal length sides and 4 equal angles
  • The result of multiplying Length by the width
  • Open public area in the middle of the town
  • verb
  • To make something balance or be equal
  • To multiply a number by itself, e.g. 2x2 or 6x8
  • To straighten the edge to form a four-sided shape

tell

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US / tel /

UK / tɛl /

A1
  • verb
  • To (strongly) advise a person to do something
  • To be able to guess
  • To say or communicate information to someone
  • To inform, but without speaking; indicate
  • To have a negative effect on someone
  • To order someone to do something; command
  • To recognize something based on certain signs
  • To report something to an authority
  • To explain something or teach someone something

straightforward

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US / ˌstreɪtˈfɔ:wəd /

UK / stretˈfɔrwəd /

B1
  • adjecitve
  • Easy to do or understand; not complicated

get

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US / ɡet /

UK / ɡɛt /

A1
  • verb
  • To become affected by illness or disease
  • To begin to feel or understand an emotion or idea
  • To send or bring someone or something home, etc.
  • To go somewhere to obtain something
  • To (cause to) do a particular thing
  • To obtain, receive or be given something
  • To currently have
  • To prepare for use
  • To understand something being said or read

hard

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US / hɑ:d /

UK / hɑː(r)d /

A1
  • adjecitve
  • Difficult to do; difficult to understand
  • (Of facts) not able to be misunderstood; clear
  • (Of alcohol) strong
  • Involving or requiring lots of work, effort, care
  • Being full of pain, trouble, and problems
  • Strong
  • (Of edge) clear; sharp
  • Difficult to bend, break or cut; solid
  • adverb
  • With lots of force, power, or impact

example

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US / ɪgˈzɑ:mpl /

UK / ɪɡˈzæmpəl /

A1
  • noun
  • Thing, person which represents a category

method

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US / 'meθəd /

UK / ˈmɛθəd /

A2
  • noun
  • (Organized and planned) way of doing something

again

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US / ə'ɡen /

UK / əˈɡɛn /

A1
  • adverb
  • One more time, once more

about

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US / ə'baʊt /

UK / əˈbaʊt /

A1
  • adverb
  • To be ready to; going to
  • Nearly; approximately; roughly
  • Near; next to; close to
  • In every direction; in the area of
  • preposition
  • Concerning or of (a topic)

even

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US / 'i:vn /

UK / ˈivən /

A1
  • adjecitve
  • Being equal in influence, power, possibility etc.
  • Being divided equally or fairly
  • (Of teams/contest) with similar chances of success
  • Smooth, level, or regular
  • Can be divided by 2; ending in 2, 4, 6, 8, or 0
  • At a regular, equally steady manner
  • Remaining steady and unchanging
  • adverb
  • (When this is surprising) as well; too
  • (Used to compare two things/stress the difference)
  • verb
  • To make something level; to flatten
  • To make something equal

like

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US / laɪk /

UK / laɪk /

A1
  • adjecitve
  • Being equal in status or kind to something else
  • Similar; the same
  • adverb
  • For example
  • preposition
  • Used as a filler; used to ad emphasis
  • In a way similar to the way something is done
  • Such as; for example
  • verb
  • To want to
  • To find something pleasing; to prefer something

people

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US / 'pi:pl /

UK / ˈpipəl /

A1
  • noun
  • Persons sharing culture, country, background, etc.
  • Men, Women, Children

that

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US / ðæt /

UK / ðæt, ðət /

A1
  • adjecitve
  • The person or thing being talked about
  • Used to identify something both the speakers know
  • adverb
  • Used to reinforce adjectives and adverbs
  • To such a degree
  • conjunction
  • Used to connect a noun clause
  • Used to introduce an adverbial clause
  • Used to introduce a noun clause
  • determiner
  • Used as a noun to refer to something
  • pronoun
  • Referring an object far away
  • Used to refer to the relative pronoun ‘which’

what

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US / wɒt /

UK / hwɑt, hwʌt, wɔt, wʌt,hwət, wət /

A1
  • pronoun
  • Thing or things that; the same kind as
  • Used to emphasize something you are about to say
  • adjecitve
  • Used to refer to a particular amount, or number
  • Used to place emphasis on a particular quality
  • adverb
  • To a certain degree
  • determiner
  • Question words used for asking for information
  • exclamation
  • Used to express excitement, shock, or surprise
  • Used to ask people to repeat something they said

enough

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US / ɪˈnʌf /

UK / ɪˈnʌf /

A1
  • adjecitve
  • Sufficient to answer the need
  • adverb
  • To a satisfactory degree
  • pronoun
  • Equal to what is needed; as much as required
  • Adequate number or amount

watch

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US / wɒtʃ /

UK / wɑtʃ /

A1
  • noun
  • Period of time someone is responsible for guarding
  • Device you wear on your wrist that shows the time
  • Official warning statement, e.g. of bad weather
  • verb
  • To keep in check, manage, or control something
  • To look at something for entertainment, e.g. TV
  • To guard a place or people; protect child, etc.
  • To look at carefully to work out what is happening
  • To protect and care for someone or something
  • Subtitles section
  • So we've got a circle here-- doesn't look like a perfect circle, but we can use our imaginations --and let's say it's got a radius of 3 meters.
  • My question, or the question we're going to answer in this video is what is the area of this circle?
  • And remember, the area is just how much space this circle takes up on a surface, or on this computer screen that you're watching, or on this piece of paper.
  • If this was a room, it's how much carpeting you would need to fill out this circular room.
  • That's what the area is.
  • Now, I'm not going to prove it to you, and we'll do that later, but the area for circle just takes on a fairly straightforward formula and I want to just get you used to applying that formula.
  • So the area of a circle is equal to pi.
  • Remember, pi was that number that people figured out was the ratio between the circumference and the diameter of the circle.
  • It's 3.14159, keeps going on and on and on.
  • It's just the number, but it's a very magical number.
  • Pi times the radius squared.
  • In fact another way of defining pi:-- you could even rewrite this right here --the area over your radius squared- so this is your radius.
  • If you multiply the radius times itself you could imagine that would be the area of a cube that's like that --that the ratio between the area of this entire circle and the ratio of this cube right here-- or this square.
  • I shouldn't say a cube.
  • Cube would be if we went into 3D --but the ratio of the area of the circle to this square right here is also equal to pie.
  • That could be actually an alternate way of defining what pi is.
  • And if you were to measure it very carefully using-- there's thousands of methods you could do it --you would get 3.14159 and keep going on and on and on.
  • But we're not going to delve too deeply into that.
  • Maybe one day I'll make a whole play list on pi.
  • But we just need to know that the area is equal to pi times r squared, so let's just apply the numbers here.
  • So in our example, the area is equal to pi times 3 meters squared, which is equal to pi times 9 meters squared, or the conventional way to write this is, equal to 9pi meters squared.
  • And remembered 9pi, the convention is just to leave it that way, but this is the same thing as 9 times 3.14159, which is probably going to be, like, 28 point something meters squared.
  • Just remember, this is just some number and it's not 9.
  • It's actually closer to 28 because it's going to be 9 times 3.14159, but we just leave it like that.
  • And that normally will be good enough for you to say, hey that is my area.
  • That's my area: 9pi.
  • Now let's go the other way: let's say I have a circle and let's say that someone would say that the area is equal to 16pi.
  • What is the diameter of that circle going to be?
  • Well, we know that area is equal to pi times the radius squared.
  • So at least let's figure out the radius.
  • So the area, 16pi, is equal to pi times our radius squared.
  • I'm just applying this formula.
  • We're just going to keep applying this formula over and over again when we're dealing with area.
  • So area, which we've been told is 16pi, is equal to pi times radius squared.
  • Now, if we divide both sides of this equation by pi, we get 16 is equal to r squared.
  • And then you take the square root of both sides and you get 4 is equal to r.
  • I guess r could also be equal to negative 4, but we're dealing with distances here; you can't have a negative radius.
  • Or at least in the world we're living in right now.
  • Just keep things simple; we just want to keep our distances positives.
  • So let's say that this has a radius of 4.
  • Now if the radius is 4, what is its diameter?
  • Well, the diameter is always going to be 2 times the radius.
  • So this 4, we're going to have another 4 there.
  • The diameter is equal to 8.
  • Now let's do a slightly harder one that will kind of compound some of the other things that we've learned in the past.
  • So let's say that I have a circle here.
  • Let's say that its circumference is equal to 20pi, and I want to know its area.
  • So way you do all these problems is just figure out everything you can, given what they've given you, and then maybe you can work out the thing they're asking for.
  • So if I know that the circumference is 25, what do I know about its radius?
  • Well, we saw in the last video that the circumference is equal to 2pi times the radius.
  • So if the circumference is equal to 20pi, we could write that 20pi is the circumference is equal to 2pi times the radius.
  • Now if you divide both sides of this by pi, those cancel out.
  • Then if you divide both sides by 2, this becomes a 1, this becomes a 10, or you get the radius is equal to 10.
  • Which makes sense, right?
  • 2pi times 10 is going to be equal to 20pi.
  • So we've figured out our radius.
  • Now, we know that the area is equal to pi times r squared.
  • And lucky for us, using the circumference, we were able to figure out the radius.
  • Now using the radius, we can figure out the area.
  • So the area is going to be equal to pi times r squared,-- r is 10 --times 10 squared, which is equal to pi times 100.
  • Or it's equal to 100pi.
  • Just like that.
  • so your circumference was 20pi, when you went around the circle, but your area of your circle is 100pi.
  • And if I gave you units it would be 100pi units squared.
  • That is your area right there: 100pi.
  • Anyway, I think that's pretty good initial exposure to the area of a circle.
  • I'll see in the next video.