Primitive Perfect Isosceles Right Triangled Square

Title: _r 19:142BR3of4 GHM

Order: 19

Horizontal side: 142 Vertical side: 142

Elements: 6√2, 8√2, 12, 16, 12√2, 16√2, 24, 18√2, 21√2, 24√2, 29√2, 42, 34√2, 50, 58, 42√2, 50√2, 84, 92.

Code: 925 0 50 841 84 142 342 118 108 581 142 142 180 118 108 166 84 74 242 124 66 241 124 90 122 136 78 121 136 90 62 142 84 426 100 42 165 84 58 84 92 50 296 71 29 507 0 50 500 50 50 214 71 29 425 100 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)

92
84
34√2
58
18√2
16√2
24√2
24
12√2
12
6√2
42√2
16
8√2
29√2
50
50√2
21√2
42