Pentagonal Orthobirotunda
The pentagonal orthobirotunda is a convex equilateral orthobirotunda having regular pentagonal upper and lower faces arranged symmetrically about the
midplane. It is Johnson solid 👁 J_(30)
.
The unit pentagonal orthobirotunda has volume
and Dehn invariant
where the first expression uses the basis of Conway et al. (1999). It can be dissected into the regular icosidodecahedron, from which it differs only by the relative rotation of the top and bottom rotundas.
See also
Bicupola, Johnson SolidExplore with Wolfram|Alpha
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References
Conway, J. H.; Radin, C.; and Sadun, L. "On Angles Whose Squared Trigonometric Functions Are Rational." Discr. Computat. Geom. 22, 321-332, 1999.Johnson, N. W. "Convex Polyhedra with Regular Faces." Canad. J. Math. 18, 169-200, 1966.Referenced on Wolfram|Alpha
Pentagonal OrthobirotundaCite this as:
Weisstein, Eric W. "Pentagonal Orthobirotunda." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/PentagonalOrthobirotunda.html
