Chapter 3 - Equations and Problem Solving - 3.1 - Solving First-Degree Equations - Problem Set 3.1 - Page 100: 78

$h=12$

We start with the given equation: $V=\frac{1}{3}Bh$ We plug in the values for $V$ and $B$: $216=\frac{1}{3}(54)h$ We simplify the right side of the equation by multiplying: $216=18h$ We are trying to get $h$ by itself. In order to do so, we must divide by $18$ on each side of the equation and then simplify: $$\frac{216}{18}=\frac{18h}{18}$$$$h=12$$