Answer
The volume is:
$V = \pi h(R+r)(R-r)$
Work Step by Step
We know the volume of a cylinder is $\pi h(r^2)$. The radius is equal to the big radius minus the small radius, so we obtain: $V= \pi h(R^2 - r^2)$. Using a difference of two squares factoring method, this simplifies to: $V = \pi h(R+r)(R-r)$.