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A regular polygon is a polygon which is both equilateral and equiangular.

That is, in which all the sides are the same length, and all the vertices have the same angle:



The center of a regular polygon $P$ is defined as the point which is the center of $P$.


In the above, $O$ is the center of the regular polygon.

Also known as

In Euclid's The Elements, a regular polygon is referred to as an equilateral and equiangular polygon.

Some sources use the word perfect or symmetrical instead of regular.


Specific instances of regular polygons with specific numbers of sides are as follows:

The term regular $n$-gon is usually used nowadays to specify a regular polygon with a specific number, that is $n$, sides.

The specific name is usually invoked only in order to draw attention to the fact that such a regular polygon has a particularly interesting set of properties.

Also see