Question

Circle O has a circumference of 36π cm. What is the length of the radius, r?

Answer 1

The length of the radius, r is 18 cm.

Explanation:

If the radius of a circle is r, then the circumference of the circle is

`C=2\pi r`

It is given that circle O has a circumference of 36π cm.

`36\pi=2\pi r`

Divide both sides by 2π.

`(36\pi)/(2\pi)=(2\pi r)/(2\pi)`

`18=r`

Therefore the length of the radius of the circle is 18 cm.