# Gyroelongated square bipyramid

Gyroelongated square bipyramid
Type Johnson
J16 - J17 - J18
Faces 2.8 triangles
Edges 24
Vertices 10
Vertex configuration 2(34)
8(35)
Symmetry group D4d, [2+,8], (2*4)
Rotation group D4, [2,4]+, (422)
Dual polyhedron Truncated square trapezohedron
Properties convex, deltahedron

In geometry, the gyroelongated square bipyramid is one of the Johnson solids (J17). As the name suggests, it can be constructed by gyroelongating an octahedron (square bipyramid) by inserting a square antiprism between its congruent halves. It is a deltahedron.

A Johnson solid is one of 92 strictly convex polyhedra that have regular faces but are not uniform (that is, they are not Platonic solids, Archimedean solids, prisms or antiprisms). They were named by Norman Johnson, who first listed these polyhedra in 1966.[1]

## Dual polyhedron

The dual of the gyroelongated square bipyramid is a square truncated trapezohedron with 10 faces: 8 pentagons and 2 square.

Dual gyroelongated square bipyramid Net of dual