This model can be used in Geometry Class to demonstrate how the volume of a pyramid can be calculated:

• The base area and height of the colored pyramids corresponds to the base area and height of the (transparent) prism.
• All three pyramids have the same volume.
• If you fill them correctly into the prism box, you will get a perfect fit. Hence, the volume of a pyramid is ⅓ of the volume of the prism.

I printed everything with a 0.4mm nozzle at a 0.2mm layer height. The prism box was printed in transparent PETG (3 perimeters), and the three pyramids in PLA. Print with (at least) a 5mm brim to prevent warping at the corners.

You have the option to insert 6mm x 3mm (diameter x height) round magnets in the pyramids, so that they stick together (good for demonstration purposes). 1mm smaller should work too, but the pyramids won't stick as well.

If you want to insert mangets, you will have to pause the print. Use the orientation provided in the “.3mf”-files. The brim and the pause are already added in the “.3mf”-files.  If you do not want to insert magnets, you can simply print the “.stl”-files as usual without pausing your print.