Question

A circular picture is 8 inches in diameter.

Answer 1

The formula of an area of a circle with radius r:

$A=\pi r^2$

Part A.

We have diameter of the circle d = 8 in. The diameter of a circle is equal two times length of a radius.

Therefore:

$r=\dfrac{d}{2}\to r=\dfrac{8}{2}=4\ in$

Calculate the area:

$A=\pi\cdot4^2=16\pi\ in^2$

Answer: C. 16π square inches.

Part 2.

Look at the picture.

Total area:

$A=\pi\cdot6^2=36\pi\ in^2$

Answer: C. 36π square inches