Copy of 12.1b Volume of a Pyramid
Derivation of the volume of a pyramid via a prism, whose volume is known. Again, notice that the result can then be extended to other pyramids and cones by using Cavalieri's principle.
Follow the directions on the screen. After you click "Investigate the 3 pyramids," you should check/uncheck "Volume=Volume" and "Volume=Volume" to convince yourself that the 3 pyramids have equal volumes.
If you wish, you are able to adjust the shape of the triangular base by moving its vertices.