#### Answer

$h=\dfrac{S-2\pi r^{2}}{2\pi r}$

#### Work Step by Step

$S=2\pi rh+2\pi r^{2}$, for $h$
Substract $2\pi r^{2}$ to both sides of the equation:
$2\pi rh+2\pi r^{2}-2\pi r^{2}=S-2\pi r^{2}$
$2\pi rh=S-2\pi r^{2}$
Divide both sides of the equation by $2\pi r$:
$\dfrac{2\pi rh}{2\pi r}=\dfrac{S-2\pi r^{2}}{2\pi r}$
$h=\dfrac{S-2\pi r^{2}}{2\pi r}$