正多边形是所有角都相等、并且所有边都相等的简单多边形，简单多边形是指在任何位置都不与自身相交的多边形。

所有具有同样边数的正多边形都是相似多边形。

• 等边三角形
• 正方形
• 正五边形
• 正六边形
• 正八边形
• 正十边形
• 正十二边形

In Euclidean geometry, a regular polygon is a polygon that is equiangular (all angles are equal in measure) and equilateral (all sides have the same length). Regular polygons may be convex or star. In the limit, a sequence of regular polygons with an increasing number of sides becomes a circle, if the perimeter is fixed, or a regular apeirogon, if the edge length is fixed.