Definition:Polygon/Regular

Definition
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:


 * RegularPolygon.png

Also known as
In, a regular polygon is referred to as an equilateral and equiangular polygon.

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

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


 * $3$ sides: Equilateral Triangle
 * $4$ sides: Square
 * $5$ sides: Regular Pentagon
 * $6$ sides: Regular Hexagon
 * $7$ sides: Regular Heptagon
 * $8$ sides: Regular Octagon
 * $9$ sides: Regular Nonagon or Regular Enneagon
 * $10$ sides: Regular Decagon
 * $11$ sides: Regular Hendecagon or Regular Undecagon
 * $12$ sides: Regular Dodecagon


 * $17$ sides: Regular Heptadecagon

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

 * Regular Polygon can be Inscribed in Circle