Non-ultraperfect Perfect Isosceles Right Triangled Square

Title: e 10:21PA4of4

Order: 10

Horizontal side: 21 Vertical side: 21

Elements: 1√2, 2, 2√2, 4, 4√2, 6, 7, 7√2, 14, 21.

Code: 217 0 21 143 21 7 70 7 7 61 13 7 45 13 3 44 17 3 73 21 0 25 13 1 24 15 1 14 14 0

The fact that every NPIRTS has a subdivided triangle is not recorded as a property. The properties below may precede order:side in a tiling's title:

• e = elegant. No tiling is just a T-junction. Such tilings may be considered aesthetically pleasing.
• p/r = pseudotriangular/rectangular inclusion subdivided into at least 6/5 triangles respectively.

Credit for Discovery

Jasper D. Skinner found many NPIRTS's before this catalogue was built by Geoffrey H. Morley. Only the two lowest order NPIRTS's are attributed to discoverers:

J. Douglas and E.P. Starke (D&S, United States) (7:10PA only)

Arthur H. Stone (AHS, United States, 1916-2000) (7:7PA only)