Catalan Solids

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Rhombic Triacontahedron
Vertices:  32  (20[3] + 12[5])
Faces:30  (rhombi)
Edges:60  (equal length)
Symmetry:  Full Icosahedral  (Ih)
Dihedral Angle:  acos(−(1+sqrt(5))/4)    144 degrees
Dual Solid:  Icosidodecahedron
(values below based on unit-edge-length Icosidodecahedron)
Edge Length:  sqrt(10*(5+sqrt(5)))/8    ≈1.0633135104400499152
Rhombus Length:  (5+sqrt(5))/4    ≈1.8090169943749474241
Rhombus Width:  sqrt(5)/2    ≈1.1180339887498948482
[3]-Vertex Radius (20):  (5*sqrt(3)+sqrt(15))/8    ≈1.5666546730064754191
[5]-Vertex Radius (12):  sqrt(5*(5+2*sqrt(5)))/4    ≈1.7204774005889669228
Edge-scribed Radius:  sqrt(5+2*sqrt(5))/2    ≈1.5388417685876267013
Inscribed Radius:  (5+3*sqrt(5))/8    ≈1.4635254915624211362
Volume:25*(5+2*sqrt(5))/16    ≈14.800212429686842801

References:[1]Johannes Kepler, Strena Seu de Nive Sexangula
[A New Year's Gift of Hexagonal Snow] (1611).
[2]Johannes Kepler, translated by Colin Hardie,
The Six-Cornered Snowflake. Oxford: Clarendon Press (1966).
[3]Eugène Catalan, Mémoire sur la Théorie des Polyèdres,
Journal de l'École polytechnique 41 (1865), 1-71, +7 plates.