Solve b/2pi:r*360=A/r^2:pi*360

$$\frac { b } { 2 \pi } : r \cdot 360 = \frac { A } { r ^ { 2 } } : \pi \cdot 360$$

Solve for A

$$A=\frac{br}{2}$$

$$r\neq 0$$

Steps for Solving Linear Equation

Cancel out 360 on both sides.

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

Multiply both sides of the equation by r.

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

Express r\times \frac{A}{r^{2}} as a single fraction.

$$\frac{b}{2\pi }=\frac{rA}{r^{2}}\pi ^{-1}$$

Cancel out r in both numerator and denominator.

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

Express \frac{A}{r}\pi ^{-1} as a single fraction.

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

Swap sides so that all variable terms are on the left hand side.

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

Multiply both sides of the equation by r.

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

Reorder the terms.

$$\frac{1}{\pi }A=\frac{1}{2}\times \frac{1}{\pi }br$$

Express \frac{1}{\pi }A as a single fraction.

$$\frac{A}{\pi }=\frac{1}{2}\times \frac{1}{\pi }br$$

Multiply \frac{1}{2} times \frac{1}{\pi } by multiplying numerator times numerator and denominator times denominator.

$$\frac{A}{\pi }=\frac{1}{2\pi }br$$

Express \frac{1}{2\pi }b as a single fraction.

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

Express \frac{b}{2\pi }r as a single fraction.

$$\frac{A}{\pi }=\frac{br}{2\pi }$$

The equation is in standard form.

$$\frac{1}{\pi }A=\frac{br}{2\pi }$$

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

$$\frac{\frac{1}{\pi }A\pi }{1}=\frac{br}{2\pi \times \frac{1}{\pi }}$$

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

$$A=\frac{br}{2\pi \times \frac{1}{\pi }}$$

Divide \frac{br}{2\pi } by \pi ^{-1}.

$$A=\frac{br}{2}$$

Solve for b

$$b=\frac{2A}{r}$$

$$r\neq 0$$