Alhambra, Sala de las dos Hermanas

• The symmetry group of the tiling is *442 (p4m).
• All the internal angles of the constituent polygons are a multiple of 45°.
• Contains 7 regular two-pointed star polygons with vertex angle of 45°.
• Contains three regular four-pointed star polygons with vertex angle of 45°.
• Contains one regular 8-pointed star polygon with vertex angle of 90°.
• Contains three regular 8-pointed star polygons with vertex angle of 45°.
• There are 9 non-regular reflective tiles.
• The tiling satisfies the interlace condition and has three finite interlaces and three infinite interlaces.
• The tiling is edge-to-edge.
• As drawn, contains about 635 polygons.

• Photo from David Wade (Base of arch, inside entrance, Colour from the original) of Not specific. Personal Communication, Information sent to the author, 21 century . [pc]
• Photo from Nick Crossling (Wood inlay from a side gallery of the Hall of Two Sisters) of Not specific. Personal Communication, Information sent to the author, 21 century . [pc]

• Wade photo SPA 1803

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