In geometry, the medial disdyakis triacontahedron is a nonconvex isohedral polyhedron. It is the dual of the uniform truncated dodecadodecahedron. It has 120 triangular faces.
Proportions The triangles have one angle of arccos ( − 1 10 ) ≈ 95.739 170 477 27 ∘ {\displaystyle \arccos(-{\frac {1}{10}})\approx 95.739\,170\,477\,27^{\circ }} , one of arccos ( 3 8 + 11 40 5 ) ≈ 8.142 571 179 89 ∘ {\displaystyle \arccos({\frac {3}{8}}+{\frac {11}{40}}{\sqrt {5}})\approx 8.142\,571\,179\,89^{\circ }} and one of arccos ( − 3 8 + 11 40 5 ) ≈ 76.118 258 342 85 ∘ {\displaystyle \arccos(-{\frac {3}{8}}+{\frac {11}{40}}{\sqrt {5}})\approx 76.118\,258\,342\,85^{\circ }} . The dihedral angle equals arccos ( − 9 11 ) ≈ 144.903 198 772 42 ∘ {\displaystyle \arccos(-{\frac {9}{11}})\approx 144.903\,198\,772\,42^{\circ }} . Part of each triangle lies within the solid, hence is invisible in solid models.
References Wenninger, Magnus (1983), Dual Models, Cambridge University Press, ISBN 978-0-521-54325-5, MR 0730208
External links Weisstein, Eric W. "Medial disdyakis triacontahedron". MathWorld.




