Grand tridecagram

Grand tridecagram
(OFF file)
Rank	2
Type	Regular
Notation
Bowers style acronym	Gat
Coxeter diagram	x13/6o ()
Schläfli symbol	{13/6}
Elements
Edges	13
Vertices	13
Vertex figure	Dyad, length 2cos(6π/13)
Measures (edge length 1)
Circumradius	${\frac {1}{2\sin {\frac {6\pi }{13}}}}\approx 0.50367$
Inradius	${\frac {1}{2\tan {\frac {6\pi }{13}}}}\approx 0.060711$
Area	${\frac {13}{4\tan {\frac {6\pi }{13}}}}\approx 0.39462$
Angle	${\frac {\pi }{13}}\approx 13.84615^{\circ }$
Central density	6
Number of external pieces	26
Level of complexity	2
Related polytopes
Army	Tad, edge length $2\cos {\frac {6\pi }{13}}$
Dual	Grand tridecagram
Conjugates	Tridecagon, Small tridecagram, Tridecagram, Medial tridecagram, Great tridecagram
Convex core	Tridecagon
Abstract & topological properties
Flag count	26
Euler characteristic	0
Schläfli type	{13}
Orientable	Yes
Properties
Symmetry	I2(13), order 26
Convex	No
Nature	Tame

The grand tridecagram is a non-convex polygon with 13 sides. It's created by taking the fifth stellation of a tridecagon. A regular grand 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 great tridecagram.

External links

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

• Wikipedia contributors. "Tridecagram".