# Bicone

A bicone or dicone (bi- comes from Latin, di- from Greek) is the three-dimensional surface of revolution of a rhombus around one of its axes of symmetry. Equivalently, a bicone is the surface created by joining two congruent right circular cones base-to-base.

A bicone has circular symmetry and orthogonal bilateral symmetry.

## Geometry

For a circular bicone with radius R and height center-to-top H, the formula for volume becomes

${\displaystyle V={\frac {2}{3}}\pi R^{2}H.}$

For a right circular cone, the surface area is

${\displaystyle SA=2\pi RS\,}$   where   ${\displaystyle S={\sqrt {R^{2}+H^{2}}}}$   is the slant height.

## Related polyhedra

A bicone can be seen as a polyhedral limiting case of an n-gonal bipyramid where n approaches infinity. It can also be seen as a dual of a cylinder as an infinite-side prism.[1]