# Special Collection: Triangles in a square

There are 10 entries in this table of similar, but not identical, triangles tiling a square.
The two properties are the number of triangles and the smallest angle of the triangles, which
are all right-angled triangles.
A paper giving the method devised by Tony Lee appears here.
Smallest angle (degrees) | Number of triangles | Link |

29.676233031 | 8 | link |

45 | 7 | link |

45 | 9 | link |

45 | 11 | link |

29.676233031 | 7 | link |

17.4790985769 | 9 | link |

13.1717770838 | 11 | link |

34.3068051241 | 7 | link |

42.324744804 | 9 | link |

43.898235765 | 11 | link |

NB. The colours are chosen at random.
It is known that a square can the tiled with similar triangles which do not have right angles.
See Laczkovich, M. Tilings of polygons with similar triangles. Combinatorica, Vol 10, pp281-306. (1990).
The triangles must be one of three similarity classes with angles of (π/8, π/4, 5π/8), (π/4, π/3, 5π/12) or (π/12, π/4, 2π/3).
Examples of these have not been produced since examples with a small number of triangles are
not known.

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