Square orthobicupola

Infobox Polyhedron with net

---

Polyhedron_Type=Johnson
"J"₂₇ - J₂₈ - J₂₉
Face_List=8 triangles
2+8 squares
Edge_Count=32
Vertex_Count=16
Symmetry_Group=D_4h
Vertex_List=8(3².4²)
8(3.4³)
Dual=-
Property_List=

---

In geometry, the square orthobicupola is one of the Johnson solids ("J"₂₈). As the name suggests, it can be constructed by joining two square cupolae ("J"₄) along their octagonal bases, matching like faces. A 45-degree rotation of one cupola before the joining yields a square gyrobicupola ("J"₂₉).

The "square orthobicupola" is the second in an infinite set of orthobicupolae.

The square orthobicupola can be elongated by the insertion of an octagonal prism between its two cupolae to yield a rhombicuboctahedron, or collapsed by the removal of an irregular hexagonal prism to yield an elongated square dipyramid ("J"₁₅), which itself is merely an elongated octahedron.

The 92 Johnson solids were named and described by Norman Johnson in 1966.

External links

* [http://mathworld.wolfram.com/JohnsonSolid.html Johnson Solid -- from MathWorld]