The five Girih tiles (from the Persian word meaning "knot") are the fundamental patterns of Islamic art, in use since the 13th century. A tile has every edge of the same length, interior angles from the set 72°, 108°, 144°, or 216°, and a polygonal line that meets the sides at the midpoints; when two tiles touch on a common side, the two line segments form a straight angle. Girih tiles closely resemble Penrose tiles.[more]
To rotate a piece, click near the center of a tile. To translate a piece, click not too close to the center and drag.[less]
 Wikipedia. "Girih Tiles." (Oct 18, 2012) en.wikipedia.org/wiki/Girih_tiles.
 S. R. Prange, "The Tiles of Infinity," Saudi Aramco World, 60(5), 2009 pp. 24–31.
 P. J. Lu and P. J. Steinhardt, "Decagonal and Quasicrystalline Tilings in Medieval Islamic Architecture," Science, 315(5815), 2007 pp. 1106-1110.