Elongated square cupola

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Elongated square cupola
Elongated square cupola.png
Type Johnson
J18J19J20
Faces 4 triangles
13 squares
1 octagon
Edges 36
Vertices 20
Vertex configuration 8(42.8)
4+8(3.43)
Symmetry group C4v
Dual polyhedron -
Properties convex
Net
Johnson solid 19 net.png

In geometry, the elongated square cupola is a polyhedron constructed from an octagonal prism by attaching square cupola onto its base. It is an example of Johnson solid.

Contents

Construction

The elongated square cupola is constructed from an octagonal prism by attaching a square cupola onto one of its bases, a process known as the elongation. [1] This cupola covers the octagonal face so that the resulting polyhedron has four equilateral triangles, thirteen squares, and one regular octagon. [2] It can also be constructed by removing a square cupola from a rhombicuboctahedron, which would also make it a diminished rhombicuboctahedron. A convex polyhedron in which all of the faces are regular polygons is the Johnson solid. The elongated square cupola is one of them, enumerated as the nineteenth Johnson solid . [3]

Properties

The surface area of an elongated square cupola is the sum of all polygonal faces' area. Its volume can be ascertained by dissecting it into both a square cupola and a regular octagon, and then adding their volume. Given the elongated triangular cupola with edge length , its surface area and volume are: [4] Its circumradius is: [5]

References

  1. Rajwade, A. R. (2001), Convex Polyhedra with Regularity Conditions and Hilbert's Third Problem , Texts and Readings in Mathematics, Hindustan Book Agency, p. 8489, doi:10.1007/978-93-86279-06-4, ISBN   978-93-86279-06-4 .
  2. Berman, Martin (1971), "Regular-faced convex polyhedra", Journal of the Franklin Institute, 291 (5): 329–352, doi:10.1016/0016-0032(71)90071-8, MR   0290245 .
  3. Francis, Darryl (August 2013), "Johnson solids & their acronyms", Word Ways, 46 (3): 177.
  4. 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, S2CID   122006114, Zbl   0132.14603 .
  5. Braileanu, Patricia Isabela; Cananau, Sorin; Dobrescu, Tiberiu Gabriel; Pascu, Nicoleta-Elisabeta (2022), "Finite Element Analysis of Metal Structure Based on Elongated Johnson Cupola", Proceedings in Manufacturing Systems, 17 (3): 89–95, ISSN   2067-9238 .