This is a “put-together” puzzle made up of two identical pieces that, when placed together, make a pyramid or tetrahedron (a 3-sided pyramid).
At first glance, this puzzle looks too simple to be worthwhile but it is challenging enough to leave on any coffee table for all to try.
The Pyramid Puzzle can be made using any thickness of wood over 1-1/2”. Tip the saw blade to 30 degrees away from square and cut as shown in Figure 1. Use a hand plane, sander or jointer to smooth the surfaces of the triangular pieces of wood. Cut the pieces to length. Make sure that the flat piece at the bottom is exactly the same length as it is wide.
When each piece is sanded and finished, it is definitely a puzzle worth having. To make this a more challenging puzzle, each piece can be divided into two sections, as show, to make an even more challenging, four piece pyramid.
Find the solution here.