Elongated pentagonal gyrocupolarotunda

Elongated pentagonal gyrocupolarotunda
Type Johnson
J40 - J41 - J42
Faces 3.5 triangles
3.5 squares
2+5 pentagons
Edges 70
Vertices 35
Vertex configuration 10(3.43)
10(3.42.5)
5(3.4.5.4)
2.5(3.5.3.5)
Symmetry group C5v
Dual polyhedron -
Properties convex
Net

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).

A Johnson solid is one of 92 strictly convex polyhedra that have regular faces but are not uniform (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

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

V=\frac{5}{12}(11+5\sqrt{5}+6\sqrt{5+2\sqrt{5}})a^3\approx16.936...a^3
A=\frac{1}{4}(60+\sqrt{10(190+49\sqrt{5}+21\sqrt{75+30\sqrt{5}})})a^2\approx33.5385...a^2

References

External links


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