Bourgoin, Plate 169

• The symmetry group of the tiling is 2*22 (cmm).
• All the internal angles of the constituent polygons are a multiple of 25.71 (π/7)°.
• Contains one regular heptagon.
• Contains one regular 14-pointed star polygon with vertex angle of 51.42 (2π/7)°.
• There are 13 non-regular reflective tiles (including 2 kites) and two reflective pairs.
• The tiling satisfies the interlace condition and has one finite interlace and three infinite interlaces with straight cross-overs.
• The tiling is edge-to-edge.
• As drawn, contains about 499 polygons.

1. Photo from David Wade, EGY 1217 (al-Mu'ayyad, Cairo, Egypt) of Not specific. Personal Communication, Information sent to the author, 21c. [pc] (1420AD, 823AH)
2. Page 317 of S J Abas and A S Salman. Symmetries of Islamic Geometrical Patterns, World Scientific, 1995. ISBN 981021704. [abas] {Very many patterns in black and white, no sources given.}
3. Plate 169 of J Bourgoin. Arabic Geometrical Pattern and Design, Dover, 1879. ISBN 048622924. [bourgoin] {Classical book of around 200 hand-produced patterns, in back and white.} Fuller version available on Internet.

• Wade photo BOU 169
• Wade photo EGY 1217

• Tilings not constructible by straightedge and compass

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