# Grand tridecagram

Grand tridecagram
Rank2
TypeRegular
Notation
Bowers style acronymGat
Coxeter diagramx13/6o ()
Schläfli symbol{13/6}
Elements
Edges13
Vertices13
Measures (edge length 1)
Circumradius${\displaystyle {\frac {1}{2\sin {\frac {6\pi }{13}}}}\approx 0.50367}$
Inradius${\displaystyle {\frac {1}{2\tan {\frac {6\pi }{13}}}}\approx 0.060711}$
Area${\displaystyle {\frac {13}{4\tan {\frac {6\pi }{13}}}}\approx 0.39462}$
Angle${\displaystyle {\frac {\pi }{13}}\approx 13.84615^{\circ }}$
Central density6
Number of external pieces26
Level of complexity2
Related polytopes
ArmyTad, edge length ${\displaystyle 2\cos {\frac {6\pi }{13}}}$
DualGrand tridecagram
ConjugatesTridecagon, Small tridecagram, Tridecagram, Medial tridecagram, Great tridecagram
Convex coreTridecagon
Abstract & topological properties
Flag count26
Euler characteristic0
Schläfli type{13}
OrientableYes
Properties
SymmetryI2(13), order 26
ConvexNo
NatureTame

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.