diameter (n)
/daɪˈæm.ɪ.tər/

a straight line that crosses a circle through the centre, or the length of this line

circumference (n)
/səˈkʌm.fər.əns/

the distance measured around the edge of a circle or a round object or area

height (n)
/haɪt/

the degree to which something is high or someone is tall

length (n)
/leŋθ/

the measurement of something from end to end or along its longest side

measure (v)
/ˈmeʒ.ər/

to find the exact size, amount, speed etc of something using a special tool or special equipment

radius (n)
/ˈreɪ.di.əs/

(the length of) a straight line joining the centre of a circle to its edge or the centre of a sphere to its surface

volume (n)
/ˈvɒl.juːm/

the number or amount of something in general

width (n)
/wɪtθ/

the distance from one side of something to the other

adjust (v)
/əˈdʒʌst/

to change something slightly, especially to make it more correct, effective, or suitable

decrease (v)
/dɪˈkriːs/

to become less, or to make something become less

extend (v)
/ɪkˈstend/

to increase the size of a building or area, especially by adding extra parts onto it

convey (v)
/kənˈveɪ/

to express a thought, feeling, or idea so that it is understood by other people

reinforce (v)
/ˌriː.ɪnˈfɔːs/

to make something stronger

mutually (r)
/ˈmjuː.tʃu.ə.li/

by, to, or for each of two or more people equally

secure (v)
/sɪˈkjʊər/

to get something, sometimes with difficulty

suspend (v)
/səˈspend/

to hang something from something else

notion (n)
/ˈnəʊ.ʃən/

an idea, a belief, or an understanding of something

victory (n)
/ˈvɪktəri/

the fact of winning a competition or battle, or an occasion when someone wins

peace (n)
/piːs/

a situation in which there is no war between countries or groups

belief (n)
/bɪˈliːf/

the feeling of being certain that something exists or is true