Noun
antiprism (plural antiprisms)
A polyhedron composed of two parallel copies of some particular polygon, connected by an alternating band of triangles.
A regular icosahedron is a gyroelongated pentagonal bipyramid and a biaugmented pentagonal antiprism in any of six orientations. Source: Internet
It can be decomposed into a gyroelongated pentagonal pyramid and a pentagonal pyramid or into a pentagonal antiprism and two equal pentagonal pyramids. Source: Internet
Extra regularity is obtained by the line connecting the base centers being perpendicular to the base planes, making it a right antiprism. Source: Internet
It is also a triangular antiprism in any of four orientations. Source: Internet
Star antiprism compounds also can be constructed where p and q have common factors; thus a 10/4 antiprism is the compound of two 5/2 star antiprisms. Source: Internet