Primitive Perfect Isosceles Right Triangled Square

Title: __ 19:132AH GHM

Order: 19

Horizontal side: 132 Vertical side: 132

Elements: 2, 2√2, 6√2, 12, 12√2, 17√2, 18√2, 28, 30, 32, 34, 36, 40, 30√2, 34√2, 64, 68, 49√2, 66√2.

Code: 685 0 64 664 66 66 496 83 83 170 83 83 24 68 64 300 70 66 301 100 66 325 100 34 645 0 0 401 40 64 287 40 64 125 40 24 124 52 24 186 46 18 367 64 36 23 100 34 340 98 34 341 132 34 64 46 18

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)