Rank2
TypeRegular
Notation
Bowers style acronymSped
Coxeter diagramx15/2o ()
Schläfli symbol{15/2}
Elements
Edges15
Vertices15
Vertex figureDyad, length (1+5+30-65)/4
Measures (edge length 1)
Circumradius${\displaystyle {\sqrt {\frac {4-{\sqrt {5}}+{\sqrt {15-6{\sqrt {5}}}}}{2}}}\approx 1.22930}$
Inradius${\displaystyle {\frac {\sqrt {7-2{\sqrt {5}}+2{\sqrt {15-6{\sqrt {5}}}}}}{2}}\approx 1.12302}$
Area${\displaystyle {\frac {15{\sqrt {7-2{\sqrt {5}}+2{\sqrt {15-6{\sqrt {5}}}}}}}{4}}\approx 8.42264}$
Angle132°
Central density2
Number of external pieces30
Level of complexity2
Related polytopes
ArmyPed, edge length ${\displaystyle {\frac {2-{\sqrt {5}}+{\sqrt {15-6{\sqrt {5}}}}}{2}}}$
Abstract & topological properties
Flag count30
Euler characteristic0
Schläfli type{15}
OrientableYes
Properties
SymmetryI2(15), order 30
Flag orbits1
ConvexNo
NatureTame

The small pentadecagram, or sped, is a non-convex polygon with 15 sides. It's created by taking the first stellation of a pentadecagon. A regular small pentadecagram has equal sides and equal angles.

It is one of three regular 15-sided star polygons, the other two being the pentadecagram and the great pentadecagram.