Equilateral polygon

In geometry, three or more than three straight lines (or segment of a line) make a polygon and an equilateral polygon is a polygon which has all sides of the same length. Except in the triangle case, it need not be equiangular (need not have all angles equal), but if it does then it is a regular polygon. If the number of sides is at least five, an equilateral polygon need not be a convex polygon: it could be concave or even self-intersecting.

All regular polygons and isotoxal polygons are equilateral.

An equilateral triangle is a regular triangle with 60° internal angles.

An equilateral quadrilateral is called a rhombus, an isotoxal polygon described by an angle α. It includes the square as a special case.

A convex equilateral pentagon can be described by two angles α and β, which together determine the other angles. Concave equilateral pentagons exist, as do concave equilateral polygons with any larger number of sides.

An equilateral polygon which is cyclic (its vertices are on a circle) is a regular polygon (a polygon that is both equilateral and equiangular).

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