Question

What is the area of a circle with a diameter that is 20 inches long? Round your answer to the nearest tenth.

Answer 1

The formula is radius^2 * pi
Since you only have the diameter you divide that by 2 since the radius is half the diameter

Now you have the radius which is 10in long.
Simply plug that into the formula to get:
10^2 * pi
= 100pi or 314.2

Answer 2

\[A = \pi r^{2}\]
\[radius = \frac{ diameter }{ 2 } = 10\]
\[A = \pi (10^{2}) = 100]\pi\]

Answer 3

Thanks!