A prism is a solid object with flat faces, identical ends and same cross section all along its length. A cross-section, on the other hand, is the shape made by cutting straight across an object. Using the Cavalieri's Principle, if the cross-sectional area of two prisms is the same, for every height above the base, their volumes will be the same. The shape which represents the cross-sectional view of these prisms is a triangle.