Question

The diameter of a circle is 8 inches. What is the area?

Answer 1

A = 1/4 * (pi) * d^2
A = 1/4 * (pi) * 8^2
A = 1/4 * (pi) * 64
A = 1/4(64) * (pi)
A = 64/4 * (pi)
A = 16 (pi) in^2

Answer 2

I believe your answer is
B. 16pi in ^2
i could be wrong though 
hope it helps!