Question

A right rectangular prism and an oblique triangular prism are both 12 centimeters tall and have the same volume. What Statement must be true about the two solids?

Answer 1

Check the picture.

The bases of the 2 prisms are on 2 parallel planes, a and b.

Let c be a third plane, between a and b, parallel to both.

Then, 

 the cross-sections A and B , of the 2 prisms, formed by plane c, have Equal Areas,

this is by Cavalier's Principle.