Noun
triacontahedron (plural triacontahedra or triacontahedrons)
A polyhedron with 30 faces.
In the rhombic triacontahedron the dihedral angle between any two adjacent rhombi is 144°, which is twice the isosceles angle of a golden triangle and four times its most acute angle. Source: Internet
The rhombic triacontahedron is a convex polytope that has a very special property: all of its faces are golden rhombi. Source: Internet