Question

What's the radius of a circle with an area of 64 square feet?

Answer 1

Area = $\pi r ^{2}$
64 = $\pi r ^{2}$
$\frac{64}{ \pi } =r^2$
$r= \frac{ \sqrt{64} }{ \sqrt{ \pi } } = \frac{8}{ \sqrt{ \pi } }$

If you want the denominator rationalized, the answer is $\frac{8 \sqrt{ \pi } }{ \pi }$