Solve A/pi=pir^2/pi

$$\frac { A } { \pi } = \frac { \pi r ^ { 2 } } { \pi }$$

Solve for A

$$A=\pi r^{2}$$

Steps for Solving Linear Equation

Cancel out \pi and \pi .

$$\frac{A}{\pi }=r^{2}$$

The equation is in standard form.

$$\frac{1}{\pi }A=r^{2}$$

Divide both sides by \pi ^{-1}.

$$\frac{\frac{1}{\pi }A\pi }{1}=\frac{r^{2}\pi }{1}$$

Dividing by \pi ^{-1} undoes the multiplication by \pi ^{-1}.

$$A=\frac{r^{2}\pi }{1}$$

Divide r^{2} by \pi ^{-1}.

$$A=\pi r^{2}$$

Solve for r

$$r=\sqrt{\frac{A}{\pi }}$$

$$r=-\sqrt{\frac{A}{\pi }}\text{, }A\geq 0$$