Regular polygons

2010 Mathematics Subject Classification: Primary: 51M05 [MSN][ZBL]

A regular polygon is a polygon, all angles of which are equal and all sides of which are equal.

In other words, a regular polygon is a polygon whose vertices all lie on one circle while its sides all touch a concentric circle. If the polygon is convex and has $n$ vertices, it is called an $n$-gon, and is denoted by $\{n\}$. If it is non-convex and its $n$ sides surround its centre $d$ times, it is called a star polygon, or a star $n$-gon of density $d$, and is denoted by $\{n/d\}$. For instance, the pentagram is $\{5/2\}$.

References

 [Co] H.S.M. Coxeter, "Regular complex polytopes", Cambridge Univ. Press (1990) pp. Chapt. 1
How to Cite This Entry:
Regular polygons. Encyclopedia of Mathematics. URL: http://www.encyclopediaofmath.org/index.php?title=Regular_polygons&oldid=27206