1. The problem statement, all variables and given/known data Find the volume, using only the variables a, b, and h in your answer. A frustum of a pyramid with square base of side b, square top of side a, and height h: 2. Relevant equations Area = length*width. Length of side S = ?? 3. The attempt at a solution I know that generally when finding volume, it's going to be the integral from a[bottom] to b[top] of a cross-section's area. usually that'd just be integral[pi*r^2] a..b for a cylinder. For this, obviously, I need to find an equation for the length side S that is a function of h, so S(h) = SL. My first thought was (b-a)h, but that wouldn't change as the integral changes, so it's out. I can't think of a dynamic equation to suit the problem, and would appreciate help pushing me in that direction.