Question

The circumference of a circle is 2.1 CM calculate its radius​

Answer 1

The radius is 0.33 cm

Explanation:

If the circumference is 2.1 cm, and say
`\pi` = 22/7

C =
`2\pi r`

If the make r the subject of formula, then we divide both sides by
`2\pi`

r = C/
`2\pi`

r = 2.1/(2*22/7)

r = 2.1/(44/7)

r = (2.1*7)/44

r = 14.7/44

r ≈ 0.33 cm

Answer 2

The radius is approximately .33 cm

Explanation:

We know the circumference of a circle is given by

C = 2*pi*r

We can approximate pi by 3.14

2.1 = 2*31.4 *r

2.1 = 6.28r

Divide each side by 6.28

2.1/6.28 = 6.28r/6.28

.334394904 =r

The radius is approximately .33 cm