The southwest iwan of the Friday Mosque of Isfahan is devided into two parts. In this activity we look at the back part (bottom of the drawing). You can see how stepwis a rectangular base is turned into an irregular octagon and then narrowed to a square, crowned by an octagonal dome.[br][list][*][color=#ffd966]Triangles [/color]in layer 0 create an octagonal tier for the next layer.[/*][*]Layer 1 is fully built up out of [color=#ff00ff]rhombuses[/color].[/*][*]Layer 2 is mainly constructed with [color=#0000ff]squares[/color].[br]They are completed by [color=#ff00ff]rhombuses [/color]and a [color=#9900ff]triangle [/color]in the back and [color=#6aa84f]bipeds [/color]aside.[/*][*]4 [color=#6d9eeb]triangles [/color]in layer 3 create a regular octagon, crowned by an octagonal dome.[/*][/list]

The 2D-drawing is from Shiro Takahashi.[list][/list]