Question

solve for r
$c = 2\pi r$

Explanation:

Step1: Isolate r by dividing both sides by $2\pi$

$\frac{C}{2\pi} = \frac{2\pi r}{2\pi}$

Step2: Simplify the right-hand side

$\frac{C}{2\pi} = r$

Answer:

$r = \frac{C}{2\pi}$