where the first expression uses the basis of Conway et al. (1999). It can be dissected into the parabiaugmented
hexagonal prism, from which it differs only by the relative positions of the
two augmented square pyramids.
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.
.
