Elongated pentagonal gyrocupolarotunda

In geometry, the elongated pentagonal gyrocupolarotunda is one of the Johnson solids (J41). As the name suggests, it can be constructed by elongating a pentagonal gyrocupolarotunda (J33) by inserting a decagonal prism between its halves. Rotating either the pentagonal cupola (J5) or the pentagonal rotunda (J6) through 36 degrees before inserting the prism yields an elongated pentagonal orthocupolarotunda (J40).

Elongated pentagonal gyrocupolarotunda
TypeJohnson
J40J41J42
Faces3x5 triangles
3x5 squares
2+5 pentagons
Edges70
Vertices35
Vertex configuration10(3.43)
10(3.42.5)
5(3.4.5.4)
2.5(3.5.3.5)
Symmetry groupC5v
Dual polyhedron-
Propertiesconvex
Net

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]

Formulae

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The following formulae for volume and surface area can be used if all faces are regular, with edge length a:[2]

 
 

References

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  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. ^ Stephen Wolfram, "Elongated pentagonal gyrocupolarotunda" from Wolfram Alpha. Retrieved July 25, 2010.
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