Dye, Figure K 9b

Opposed windwheels, Residence, Chengtu, Szechwan, 1875 AD. Also the same as Figure K 10a. Also the same as Figure I.10.2 in G & S.

This pattern is a member of an interesting class of mathematical patterns. PP Class 72, [p4g,c4,d2], IH Class 73.

Statistics on this tiling:

Tiling has symmetry p4g.
Tiling has 4 polygons (with 24 edges) of which 1 are specified as copies of others.
Edges are completely connected.
Tiling is not edge-to-edge.
Tiling satisfies the two-polygon condition.
Internal angles a multiple of 90°.
Contains one non-regular polygon which has reflective symmetry.
Contains: 2 squares.
Tiling contains 207 polygons.