Answer
F
Work Step by Step
$A=\pi*r^2$
$A/\pi=\pi*r^2/\pi$
$A/\pi=r^2$
$\sqrt{A/\pi}=\sqrt{r^2}$
$\sqrt {A/\pi} = r$
$r=\frac{\sqrt {A\pi}}{\pi}$
$r*\pi=\pi*\frac{\sqrt {A\pi}}{\pi}$
$\pi*r = \sqrt {A\pi}$
$(\pi*r)^2 = (\sqrt {A\pi})^2$
$\pi^2*r^2 = A\pi$
$\pi^2*r^2/\pi = A\pi/\pi$
$\pi*r^2=A$