The Topkapi palace in Istanbul keeps scrolls on which the decorative patter as well as the underlaying girih tiles are drawn. In the pattern in the applet below four different girih tiles are used: decagons, hexagons, bowties and rhombusses.[br]You can notice that around the intercepts of the outer lines of the tiles small polygones are being formed.[br][list][*]Most frequently it is a regular pentagon.[/*][*]A bowtie always coincides with two overlapping pentagons, forming an octagon.[/*][*]A rhombus coincides with a hexagon.[/*][/list]