In geometry, a hexagon is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°.
Giant's Causeway closeup
The ideal crystalline structure of graphene is a hexagonal grid.
Assembled E-ELT mirror segments
A beehive honeycomb
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