Acronym | pakid |
Name |
pentakis dodecahedron, apiculated dodecahedron |
© © (compound with its dual) | |
Vertex figure | [t6], [T5] |
Dihedral angles |
|
Dual | ti |
Face vector | 32, 90, 60 |
Confer |
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External links |
The triangles {(t,t,T)} have vertex angles t = arccos[(9-sqrt(5))/12] = 55.690640° resp. T = arccos[(9 sqrt(5)-7)/36] = 68.618721°.
Edge sizes used here are tT = x = 1 (short) resp. tt = a = (9-sqrt(5))/6 = 1.127322 (long).
A nice construction is shown at the right. Note that for the pentagonal pyramids the height H has to equal the base's side length B, while for the triangular pyramids the lacing edges' lengths D are equal to the base's side length B, in order to accomplish the right geometry.
Incidence matrix according to Dynkin symbol
m3m5o = fo3oo5oa&#zx → height = 0 a = (9-sqrt(5))/6 = 1.127322 o.3o.5o. | 12 * | 5 0 | 5 [T5] .o3.o5.o | * 20 | 3 3 | 6 [t6] ------------+-------+-------+--- oo3oo5oo&#x | 1 1 | 60 * | 2 x .. .. .a | 0 2 | * 30 | 2 b ------------+-------+-------+--- .. .. oa&#x | 1 2 | 2 1 | 60 {(t,t,T)}
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