Question

The diameter of a cake is 7.8 inches. What is the area of the cake?

Answer 1

A = 12.25 sq inches

Explanation:

A = (7.8/2)²π

A = 3.9²π

A = 12.25 sq inches

Answer 2

A = πr^2
The radius is half of the diameter.
r = 7.8 / 2
r = 3.9

A = π(3.9)^2
A ≈ 47.78