Great octadecagram

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Great octadecagram
Rank2
TypeRegular
Notation
Bowers style acronymGodge
Coxeter diagramx18/7o ()
Schläfli symbol{18/7}
Elements
Edges18
Vertices18
Vertex figureDyad, length 2cos(7π/18)
Measures (edge length 1)
Circumradius
Inradius
Area
Angle40°
Central density7
Number of external pieces36
Level of complexity2
Related polytopes
ArmyOd, edge length
DualGreat octadecagram
ConjugatesOctadecagon, octadecagram
Convex coreOctadecagon
Abstract & topological properties
Flag count36
Euler characteristic0
Schläfli type{18}
OrientableYes
Properties
SymmetryI2(18), order 36
ConvexNo
NatureTame

The great octadecagram, or godge, is a non-convex polygon with 18 sides. It's created by taking the sixth stellation of an octadecagon. A regular great octadecagram has equal sides and equal angles.

It is one of two regular 18-sided star polygons, the other being the octadecagram.

It is the uniform quasitruncation of the enneagram.