Small ditrigonal dodecacronic hexecontahedron explained

In geometry, the small ditrigonal dodecacronic hexecontahedron (or fat star) is a nonconvex isohedral polyhedron. It is the dual of the uniform small ditrigonal dodecicosidodecahedron. It is visually identical to the small dodecicosacron. Its faces are darts. A part of each dart lies inside the solid, hence is invisible in solid models.

Proportions

Faces have two angles of

\arccos(5+
12
1
4

\sqrt{5})12.66107880443\circ

, one of
\arccos(-5-
12
1
60

\sqrt{5})116.99639685170\circ

and one of

360\circ-\arccos(-

1-
12
19
60

\sqrt{5})217.68144553945\circ

. Its dihedral angles equal
\arccos({-44-3\sqrt{5
}})\approx 146.230\,659\,755\,53^. The ratio between the lengths of the long and short edges is
31+5\sqrt{5
}\approx 1.110\,008\,944\,41.