A frustum of a pyramid with square base of side b, square top of side a, and height h.

-what's the volume using only the variables a, b, and h in the answer?

see the other question.

To find the volume of a frustum of a pyramid with square bases, you can use the formula:

Volume = (1/3) * h * (A1 + A2 + √(A1 * A2))

Where:
- h is the height of the frustum
- A1 is the area of the larger base
- A2 is the area of the smaller base

In this case, the larger base is a square of side b, and the smaller top is a square of side a. To find the areas, we use the formulas:

A1 = b^2
A2 = a^2

Substituting these values into the volume formula, we get:

Volume = (1/3) * h * (b^2 + a^2 + √(b^2 * a^2))

So, the volume of the frustum using only the variables a, b, and h in the answer is (1/3) * h * (b^2 + a^2 + √(b^2 * a^2)).