# Solve: C=2(pi)R for R ?

$R = \setminus \frac{C}{2 \setminus \pi}$
Divide both sides by $2 \setminus \pi$ :
$\setminus \frac{C}{2 \setminus \pi} = \setminus \frac{2 \setminus \pi R}{2 \setminus \pi}$
$R = \setminus \frac{C}{2 \setminus \pi}$