Pentagonal orthocupolarotunda explained

Type:Johnson
Faces:3×5 triangles
5 squares
2+5 pentagons
Edges:50
Vertices:25
Dual:-
Properties:convex
Net:Johnson solid 32 net.png

In geometry, the pentagonal orthocupolarotunda is one of the Johnson solids . As the name suggests, it can be constructed by joining a pentagonal cupola and a pentagonal rotunda along their decagonal bases, matching the pentagonal faces. A 36-degree rotation of one of the halves before the joining yields a pentagonal gyrocupolarotunda .

Formulae

The following formulae for volume and surface area can be used if all faces are regular, with edge length a:[1]

V=5
12

\left(11+5\sqrt{5}\right)a3 ≈ 9.24181...a3

A=\left(5+1
4

\sqrt{1900+490\sqrt{5}+210\sqrt{75+30\sqrt{5}}}\right)a2 ≈ 23.5385...a2

Notes and References

  1. [Stephen Wolfram]