The dual polyhedron of an asymmetric bipyramid is a frustum. The sphere-cone is a spherical section with a frustum or blunted cone attached. Primitives which are completely outside the visual volume are discarded; This is called frustum culling. A right frustum is a parallel truncation of a right pyramid or right cone. In beam tracing, a pyramidal beam is initially cast through the entire viewing frustum. He finds the volume of rectangular prisms, pyramids, and the frustum of a square pyramid. However, actual instrument bores approximate a frustum of a cone. The biconic is a sphere-cone with an additional frustum attached. The viewing frustum is a geometric representation of the volume visible to the virtual camera. If all the edges are forced to be identical, a frustum becomes a uniform prism. The frustum is then pulled away from the SRB by the drogue chute. Often, objects lie on the boundary of the viewing frustum. The frustum and drogue parachute continue on a separate trajectory to splashdown. Further, a set of z-planes define the near and far bounds of the frustum. Problems 10 and 14 compute a surface area and the volume of a frustum respectively.