Question

the circumference of a circle can be found using the formula c = 2πr. which is an equivalent equation solved for r? r = cπ r = c(2π) r = \frac{c}{2π} r = \frac{2π}{c}

Explanation:

Step1: Isolate r

Given $C = 2\pi r$, divide both sides by $2\pi$.
$\frac{C}{2\pi}=\frac{2\pi r}{2\pi}$

Step2: Simplify

$\frac{2\pi r}{2\pi}=r$, so $r = \frac{C}{2\pi}$.

Answer:

$r=\frac{C}{2\pi}$ (the third option in the multiple - choice list)