Chapter 3 - Equations and Problem Solving - 3.2 - Equations and Problem Solving - Problem Set 3.2 - Page 106: 48

$h = $$\frac{A}{2\pi r}$$ - r$

Using the properties of equality we obtain: A = 2$\pi$$r^{2}$ + 2$\pi$rh Subtract 2$\pi$$r^{2}$ from both sides A - 2$\pi$$r^{2}$ = 2$\pi$rh Divide both sides by 2$\pi$r $\frac{A}{2\pi r}$ $- r = h$