Polyhedron with 60 faces
In geometry , the small stellapentakis dodecahedron is a nonconvex isohedral polyhedron . It is the dual of the truncated great dodecahedron . It has 60 intersecting triangular faces.
Proportions
The triangles have two acute angles of
arccos
-->
(
1
2
+
1
5
5
)
≈ ≈ -->
18.699
407
085
149
∘ ∘ -->
{\displaystyle \arccos({\frac {1}{2}}+{\frac {1}{5}}{\sqrt {5}})\approx 18.699\,407\,085\,149^{\circ }}
and one obtuse angle of
arccos
-->
(
1
10
− − -->
2
5
5
)
≈ ≈ -->
142.601
185
829
70
∘ ∘ -->
{\displaystyle \arccos({\frac {1}{10}}-{\frac {2}{5}}{\sqrt {5}})\approx 142.601\,185\,829\,70^{\circ }}
. The dihedral angle equals
arccos
-->
(
− − -->
24
− − -->
5
5
41
)
≈ ≈ -->
149.099
125
827
35
∘ ∘ -->
{\displaystyle \arccos({\frac {-24-5{\sqrt {5}}}{41}})\approx 149.099\,125\,827\,35^{\circ }}
. Part of each triangle lies within the solid, hence is invisible in solid models.
References
External links
Kepler-Poinsot polyhedra (nonconvex regular polyhedra)Uniform truncations of Kepler-Poinsot polyhedra Nonconvex uniform hemipolyhedra Duals of nonconvex uniform polyhedra Duals of nonconvex uniform polyhedra with infinite stellations