Trigon is a tile placement game by Wilhelm Kienzle from 1951 and was published by Naef in 1958. Each player gets a set of 9 similar right triangles (5 different sizes) that form a geometric sequence. All 9 tiles together form a square with a square hole in which a cube (the die) lies. A triangle is made up of two smaller ones in the sequence. The side lengths of the triangle are based on the golden section. You can find more in the book "Kurt Naef: Der Spielzeugmacher". All tiles and the box are made of wood in high quality. The game: A player rolls the die that dertemines a specific size, 6 meaning any choice. The player places the triangle on the table. In turn order, the other players place one of their triangles adjacent to the last played triangle with the same length (similar to the principle of domino). A player who cannot do so must pass. The player who gets rid of all his triangles wins. In addition, mathematical facts are presented about the Golden section, the theorem of Pythagoras and about parallelograms. There a puzzles presented to be solved as well. —user summary