The 14 tetrabolos each consist of four right isosceles triangles. These triangles touch either along their hypotenuses or along their legs—mixed connections (one hypotenuse and one leg at the same junction) do not occur.

Tetrabolos belong to the family of polyabolos, which are also known as polytans.

Martin Gardner introduced the tetrabolos in his book Mathematical Magic Show.
Together, the 14 tetrabolos form an area consisting of 56 right isosceles triangles.

The underlying grid allows shapes with up to fourfold rotational symmetry and four axes of reflection. However, there are no shapes with this maximal symmetry that can be assembled entirely from all 14 tetrabolos. Even the rectangle shown has no solution. The few known symmetrical shapes using all 14 pieces have at most a single axis of reflection.

The 3D-print templates consist of 14 Tetrabolo puzzle pieces and a box.

The Tetrabolo Puzzle solver is part of a program collection available for download on Itch.io. It is for Windows only.

IMPORTANT: For a correct installation, please read the Instructions before unpacking!

Download multi-colored crafting templates and a crafting guide for the cardboard tetrabolo puzzle