#### Answer

To use the formula for finding the area of a circle, you need to know the length of the radius. If you are given the diameter of a circle, what should you do to find the radius. Divide by two.

#### Work Step by Step

Area of a Circle: $A$ = $\pi$$r$$^{2}$
Therefore, to find the area the radius is required.
Diameter = 2$r$
Therefore: $r$ = Diameter / 2