Example of Octagon

An octagon is an 8 sided, two dimensional shape. The regular octagon is is one of the classic geometrical shapes, having eight sides of equal length.If not commonly used for much more than 'Stop' signs and umbrellas in physical form, the octagon is used in computer graphics as part of grid geometry calculation for advanced shapes. The divisions of octagons and their projected forms are used for a range of geometric elements in designs. Octagons form the basis of decorative designs in many traditional art forms. Their geometric base allows for coordination of patterns.

Examples of Octagon:

https://en.wikipedia.org/wiki/The_Octagon
https://en.wikipedia.org/wiki/Octagon

Image Example of Octagon:

A regular octagon.