antiprism
An antiprism is a prismatoid
whose bases are congruent and whose lateral faces are congruent triangles
.
An antiprism can be used to construct an icosahedron: Let be an antiprism with regular pentagons as its bases and equilateral triangles
as its lateral faces. To each base of , attach a pentagonal pyramid whose base is congruent to the bases of and whose lateral faces are equilateral triangles.
For any integer , the following are equivalent statements about an antiprism :
- 1.
has a base that is an -gon;
- 2.
has faces;
- 3.
has vertices;
- 4.
has edges.