Question

Circle O has a radius of 12 inches. find the exact length of semicircle HJI.

Answer 1

12pi

A semicircle is exactly half of a circle.

C = 2pi(r) (for full circle)

C = pi(r) (for half of a circle)

C = pi(12)

The exact measure is 12 pi inches

Answer 2

`12\pi\ in`

Explanation:

we know that

The length of a circle is equal to the circumference

`C=2\pi r`

where

r is the radius of the circle

In this problem we have

`r=12\ in`

The length of semicircle is equal to

`C=\pi r`

substitute

`C=\pi (12)`

`C=12\pi\ in`