three tetrahedrons

A triangular prism is divided into 3 tetrahedrons (or triangular pyramids). Drag G or H to fit the solids inside the prism. [br]These tetrahedrons are different in shape but their volumes are equal.[br]Drag A, B or C to change the base, or D to change the height.
To compare the volume of any pair of tetrahedrons, find two triangular faces that are congruent, one from each tetrahedron. Then identify their corresponding heights.

Information: three tetrahedrons