Primitive Perfect Isosceles Right Triangled Square

Title: __ 19:212BJ GHM

Order: 19

Horizontal side: 212 Vertical side: 212

Elements: 6√2, 12, 12√2, 16√2, 24, 32, 24√2, 29√2, 32√2, 48, 58, 64, 74, 58√2, 61√2, 90, 74√2, 122, 138.

Code: 1385 0 74 1221 122 212 612 183 151 901 212 212 290 183 151 323 154 90 582 212 64 581 212 122 164 138 74 483 154 42 747 0 74 740 74 74 324 106 42 643 212 0 244 130 18 243 154 18 124 142 6 123 154 6 64 148 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)

138
122
61√2
90
29√2
32
58√2
58
16√2
48
74
74√2
32√2
64
24√2
24
12√2
12
6√2