# Hendecagram

Hendecagram
Rank2
TypeRegular
Notation
Bowers style acronymHenge
Coxeter diagramx11/3o ()
Schläfli symbol{11/3}
Elements
Edges11
Vertices11
Measures (edge length 1)
Circumradius${\displaystyle {\frac {1}{2\sin {\frac {3\pi }{11}}}}\approx 0.66159}$
Inradius${\displaystyle {\frac {1}{2\tan {\frac {3\pi }{11}}}}\approx 0.43325}$
Area${\displaystyle {\frac {11}{4\tan {\frac {3\pi }{11}}}}\approx 2.38289}$
Angle${\displaystyle {\frac {5\pi }{11}}\approx 81.81818^{\circ }}$
Central density3
Number of external pieces22
Level of complexity2
Related polytopes
ArmyHeng, edge length ${\displaystyle {\frac {\sin {\frac {\pi }{11}}}{\sin {\frac {3\pi }{11}}}}}$
DualHendecagram
ConjugatesHendecagon, small hendecagram, great hendecagram, grand hendecagram
Convex coreHendecagon
Abstract & topological properties
Flag count22
Euler characteristic0
OrientableYes
Properties
SymmetryI2(11), order 22
Flag orbits1
ConvexNo
NatureTame

The hendecagram also called the medial hendecagram, is a non-convex polygon with 11 sides. It's created by taking the second stellation of a hendecagon. A regular hendecagram has equal sides and equal angles.

It is one of four regular 11-sided star polygons, the other three being the small hendecagram, the great hendecagram, and the grand hendecagram. The name "hendecagram" is often used to describe any of these shapes.

## Vertex coordinates

The vertex coordinates for a hendecagram are the same as those of the hendecagon.