Primitive Perfect Isosceles Right Triangled Square
Title: ___ 17:104AB GHM
Order: 17
Horizontal side: 104 Vertical side: 104
Elements: 10, 10√2, 20, 15√2, 16√2, 17√2, 18√2, 20√2, 32, 34, 36, 32√2, 33√2, 34√2, 35√2, 36√2, 38√2.
Code: 365 0 68 364 36 68 166 56 88 327 72 104 326 72 72 380 56 88 342 34 34 184 18 50 334 51 17 156 69 35 107 84 50 100 94 50 207 84 40 206 84 20 350 69 35 343 34 0 172 51 17
The properties below may precede order:side in a tiling's title:
- c = crossed. There is a tile-corner traversed by two lines. The only known crossed PPIRTS's below order 20 are 19:35AB1of4 and 19:35AB4of4.
- d = double-pentagon patterned. Every such tiling is a subdivision of an instance of the same deformable tiling by two 45-90-90-90-225 pentagons with a shared side, four triangles and two pseudotriangles. All below order 19 are degenerate in the sense that one or more sides of underlying tiles have shrunk to zero length. The non-degenerate d-tilings of order 19 are 19:221AA, 19:229AB and 19:241AA.
- e = elegant. No tile-corner is just a T-junction. Such tilings may be considered aesthetically pleasing. The only known elegant PPIRTS's below order 16 are 13:21AA, 14:26AJ, 14:35AA and 15:55AA.
- i = isomers exist which are ineligible for this catalogue. They are not included in the isomer count which follows 'of' in the tiling id.
- r = rectangular inclusion. The only known PPIRTS's below order 16 with a rectangular inclusion are 13:18AA1-4of4 and 15:44AA1-4of4.
Credit for Discovery
Just three people are credited with the discovery of Primitive Perfects:
Geoffrey H. Morley (GHM, England)
Jasper D. Skinner, II (JDS, United States)
William T. Tutte (WTT, Canada, 1917-2002) (15:44AI, 17:136AJ and 19:56AJ only)