Pink grebs, small side windows, in prayer room, Great Hassan II Mosque, Casablanca

• The symmetry group of the tiling is 2*22 (cmm).
• All the internal angles of the constituent polygons are a multiple of 45°.
• Contains one regular octagon.
• There are three non-regular reflective tiles.
• The tiling satisfies the interlace condition and has no finite interlace and two infinite interlaces with straight cross-overs.
• The tiling is edge-to-edge.
• As drawn, contains about 509 polygons.

1. Chester Beaty Library, Is 1614.2 (Qur'an) of Not specific. Personal Communication, Information sent to the author, 21c. [pc]
2. Page 153, small side windows (Hassan II Mosque, Casablanca, Morocco. No colouring in original) of Jean-Marc Castéra. Arabesques: Decorative Art in Morocco, ACR Edition, Paris, 1999. ISBN 286770124. [castera] {Beautiful book.}

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