I have been struggling with the following problem involving multiple integrals.

The question is "Find the volume of a right, circular cone of radius r and height h" a) as a single integral. b) as a double integral. c) as a triple integral.

The problem I have with multiple integrals is that I usually cannot figure out the limits to integrate over. With this problem no functions are given so I'm not sure where to start. Any help would be greatly appreciated.

Thanks!