| 1. |  | Five Tetrahedra, by Vladimir Bulatov | Metal sculpture; Icosahedra; Tetrahedra; | The icosahedral symmetry group has 60 elements – rotations about axes of order 2, 3 and 5. It has a subgroup of index 5 – the group of rotational symmetries of the tetrahedron with 12 elements given... |
