Gyroelongated pyramid

Gyroelongated pyramid
Example pentagonal form
Faces3n triangles
1 n-gon
Edges5n
Vertices2n + 1
Symmetry groupCnv, [n], (*nn)
Rotation groupCn, [n]+, (nn)
Propertiesconvex

In geometry, the gyroelongated pyramids (also called augmented antiprisms) are an infinite set of polyhedra, constructed by adjoining an n-gonal pyramid to an n-gonal antiprism.

There are two gyroelongated pyramids that are Johnson solids made from regular triangles and square, and pentagons. A triangular and hexagonal form can be constructed with coplanar faces. Others can be constructed allowing for isosceles triangles.