Great tridecagram

Great tridecagram
(OFF file)
Rank	2
Type	Regular
Space	Spherical
Notation
Bowers style acronym	Get
Coxeter diagram	x13/5o
Schläfli symbol	{13/5}
Elements
Edges	13
Vertices	13
Vertex figure	Dyad, length 2cos(5π/13)
Measures (edge length 1)
Circumradius	$\frac{1}{2\sin\frac{5\pi}{13}} ≈ 0.53475$
Inradius	$\frac{1}{2\tan\frac{5\pi}{13}} ≈ 0.18962$
Area	$\frac{13}{4\tan\frac{5\pi}{13}} ≈ 1.23256$
Angle	$\frac{3\pi}{13} ≈ 41.53846^\circ$
Central density	5
Number of external pieces	26
Level of complexity	2
Related polytopes
Army	Tad, edge length $\frac{\sin\frac{\pi}{13}}{\sin\frac{5\pi}{13}}$
Dual	Great tridecagram
Conjugates	Tridecagon, Small tridecagram, Tridecagram, Medial tridecagram, Grand tridecagram
Convex core	Tridecagon
Abstract & topological properties
Flag count	26
Euler characteristic	0
Orientable	Yes
Properties
Symmetry	I2(13), order 26
Convex	No
Nature	Tame

The great tridecagram is a non-convex polygon with 13 sides. It's created by taking the fourth stellation]] of a tridecagon. A regular great tridecagram has equal sides and equal angles.

It is one of five regular 13-sided star polygons, the other four being the small tridecagram, the tridecagram, the medial tridecagram, and the grand tridecagram.

External links

• Bowers, Jonathan. "Regular Polygons and Other Two Dimensional Shapes".

• Wikipedia Contributors. "Tridecagram".