Primitive Perfect Isosceles Right Triangled Square

Title: _d 19:194AO1of2 GHM

Order: 19

Horizontal side: 194 Vertical side: 194

Elements: 4, 3√2, 4√2, 6, 8, 6√2, 8√2, 9√2, 17√2, 34, 29√2, 34√2, 63, 68, 80, 97, 80√2, 114, 97√2.

Code: 1145 0 80 974 97 97 973 194 97 174 114 80 290 131 97 631 194 97 807 0 80 800 80 80 84 88 72 83 96 72 62 102 74 94 105 71 63 102 68 32 105 71 44 92 68 43 96 68 681 160 68 342 194 34 343 194 0

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)

114
97√2
97
17√2
29√2
63
80
80√2
8√2
8
6√2
9√2
6
3√2
4√2
4
68
34√2
34