In geometry, the small dodecicosacron (or small dipteral trisicosahedron) is the dual of the small dodecicosahedron (U50). It is visually identical to the Small ditrigonal dodecacronic hexecontahedron. It has 60 intersecting bow-tie-shaped faces.
Proportions Each face has two angles of arccos ( 5 12 + 1 4 5 ) ≈ 12.661 078 804 43 ∘ {\displaystyle \arccos({\frac {5}{12}}+{\frac {1}{4}}{\sqrt {5}})\approx 12.661\,078\,804\,43^{\circ }} and two angles of arccos ( − 3 4 + 1 20 5 ) ≈ 129.657 475 656 13 ∘ {\displaystyle \arccos(-{\frac {3}{4}}+{\frac {1}{20}}{\sqrt {5}})\approx 129.657\,475\,656\,13^{\circ }} . The diagonals of each antiparallelogram intersect at an angle of arccos ( 1 12 + 19 60 5 ) ≈ 37.681 445 539 45 ∘ {\displaystyle \arccos({\frac {1}{12}}+{\frac {19}{60}}{\sqrt {5}})\approx 37.681\,445\,539\,45^{\circ }} . The dihedral angle equals arccos ( − 44 − 3 5 61 ) ≈ 146.230 659 755 53 ∘ {\displaystyle \arccos({\frac {-44-3{\sqrt {5}}}{61}})\approx 146.230\,659\,755\,53^{\circ }} . The ratio between the lengths of the long edges and the short ones equals 1 2 + 1 2 5 {\displaystyle {\frac {1}{2}}+{\frac {1}{2}}{\sqrt {5}}} , which is the golden ratio. Part of each face lies inside 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. "Small dodecicosacron". MathWorld.
Uniform polyhedra and duals




