|Set of pyramidal frusta|
Examples: Pentagonal and square frustums
|Faces|| n trapezoids,|
Each plane section is a base of the frustum. The axis of the frustum, if any, is that of the original cone or pyramid. A frustum is circular if it has circular bases; it is right if the axis is perpendicular to both bases, and oblique otherwise.
Cones and pyramids can be viewed as degenerate cases of frustums, where one of the cutting planes passes through the apex (so that the corresponding base reduces to a point). The pyramidal frusta are a subclass of the prismatoids.
Two frusta joined at their bases make a bifrustum.
The volume of a frustum is the difference between the volume of the cone (or other figure) before slicing the apex off, minus the volume of the cone (or other figure) that was sliced off:
Let be the height of the frustum, that is, the perpendicular distance between the two planes. Considering that and , one gets the alternative formula for the volume
In particular, the volume of a circular cone frustum is
Also, the volume ratio can be written as a function of length ratios, or area ratios:
US Patent Issued to Intel on May 31 for "Apparatus and Method for a Frustum Culling Algorithm Suitable for Hardware Implementation" (California Inventor)
Jun 03, 2011; ALEXANDRIA, Va., June 3 -- United States Patent no. 7,952,574, issued on May 31, was assigned to Intel Corp. (Santa Clara, Calif...