Solution (not for the tenacious) 
This construction puzzle, which was patented in 1940 by E.T. Johnson, consists of two identical pieces and at first sight it looks easy to solve. But looks can be deceiving. This apparently easy puzzle has been the cause of many a sleepless night.
When pieced together it is a regular tetrahedron made up of regular triangles. This pyramid is known as one of the five Platonic bodies. The other four are: the hexagon (cube), the dodecahedron, the octahedron, the icosahedron. Platonic bodies are perfectly regular, i.e. the sides of the planes and the planes themselves are regular. They were discovered by Plato, hence the name.
Using the above figure, draw two identical pieces on a sheet of cardboard. Or download the figuur and cut out the figures, fold them along the yellow lines and glue them together carefully. When you have two identical stereometric figures, you can start to solve the puzzle. Making this puzzle in wood is a challenge in itself.
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