Also found in: Dictionary, Thesaurus, Medical, Wikipedia.


A polyhedron whose vertices all are in one or the other of two parallel planes.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a polyhedron in which two faces (the bases of the prismatoid) lie in parallel planes and the remaining faces are

Figure 1

triangles or trapezoids, where one side of each triangle and two sides of each trapezoid are edges of the bases (see Figure 1). The volume of a prismatoid is equal to (h/6) (S + S′ + 4S″), where h is the perpendicular distance between the bases, S and S′ are the areas of the bases, and S″ is the area of a plane section midway between the two bases.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.