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Elongated square pyramid

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Elongated square pyramid
TypeJohnson
J7 - J8 - J9
Faces4 triangles
1+4 squares
Edges16
Vertices9
Vertex configuration4(43)
1(34)
4(32.42)
Symmetry groupC4v, [4], (*44)
Rotation groupC4, [4]+, (44)
Dual polyhedronself
Propertiesconvex
Net

In geometry, the elongated square pyramid is one of the Johnson solids (J8). As the name suggests, it can be constructed by elongating a square pyramid (J1) by attaching a cube to its square base. Like any elongated pyramid, it is topologically (but not geometrically) self-dual.

A Johnson solid is one of 92 strictly convex polyhedra that is composed of regular polygon faces but are not uniform polyhedra (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 elongated square pyramid has 9 faces: 4 triangular, 1 square and 4 trapezoidal.

Dual elongated square pyramid Net of dual

Johnson solid No.8 Elongated square pyramid(Cube and Square pyramid) fill the space with Tetrahedron.[2]

See also

Elongated square bipyramid

References

  1. ^ Johnson, Norman W. (1966), "Convex polyhedra with regular faces", Canadian Journal of Mathematics, 18: 169–200, doi:10.4153/cjm-1966-021-8, MR 0185507, Zbl 0132.14603.
  2. ^ http://woodenpolyhedra.web.fc2.com/J8.html