Gyroelongated pentagonal cupolarotunda

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Gyroelongated pentagonal cupolarotunda
Gyroelongated pentagonal cupolarotunda.png
Type Johnson
J46J47J48
Faces 7×5 triangles
5 squares
2+5 pentagons
Edges 80
Vertices 35
Vertex configuration 5(3.4.5.4)
2.5(3.5.3.5)
2.5(34.4)
2.5(34.5)
Symmetry group C5
Dual polyhedron -
Properties convex, chiral
Net
Johnson solid 47 net.png

In geometry, the gyroelongated pentagonal cupolarotunda is one of the Johnson solids (J47). As the name suggests, it can be constructed by gyroelongating a pentagonal cupolarotunda ( J32 or J33 ) by inserting a decagonal antiprism between its two halves.

Contents

A Johnson solid is one of 92 strictly convex polyhedra that are 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]

The gyroelongated pentagonal cupolarotunda is one of five Johnson solids which are chiral, meaning that they have a "left-handed" and a "right-handed" form. In the illustration to the right, each pentagonal face on the bottom half of the figure is connected by a path of two triangular faces to a square face above it and to the left. In the figure of opposite chirality (the mirror image of the illustrated figure), each bottom pentagon would be connected to a square face above it and to the right. The two chiral forms of J47 are not considered different Johnson solids.

3D model of a gyroelongated pentagonal cupolarotunda J47 gyroelongated pentagonal cupolarotunda.stl
3D model of a gyroelongated pentagonal cupolarotunda

Area and volume

With edge length a, the surface area is

and the volume is

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 .