In geometry, an octagon is an eight-sided polygon or 8-gon.
The octagonal floor plan, Dome of the Rock, Quds.
Umbrellas often have an octagonal outline.
The famous Bukhara rug design incorporates an octagonal "elephant's foot" motif.
Janggi uses octagonal pieces.
In geometry, a polygon is a plane figure made up of line segments connected to form a closed polygonal chain.
Historical image of polygons (1699)
The Giant's Causeway, in Northern Ireland