Question

Please help. I've been trying to figure this out for an hour and I still don't understand how it's 72. I feel really stupid because it's probably easy to do.

Answer 1

C.
`72\pi`

Explanation:

The radius of the circle is 24 units, then the area of the whole circle is

`\pi r^2=\pi \cdot 24^2=576\pi \ un^2.`

The shaded circle is limited by 45° angle, so its area is

`(45)/(360)=(1)/(8)`

of the area of the whole circle.

The area of the shaded circle is

`(1)/(8)\cdot 576\pi =72\pi \ un^2.`