Volume of a Pyramid

The three pyramids can be combined to a cube. This allows to show, that the volume of the pyramids is one third of the volume of the cube.

The pyramids can be held together with magnets with a diameter of 10 mm and a height of 2 mm. Just add a print pause after 9.8 mm, so you can insert the magnets. (2 magnets are needed per pyramid.)

Since the pyramids all need to be the same size, I just uploaded one file which can simply be printed three times.