The Compendium Geometry is an eBook providing facts, formulas and explanations about geometry.


A trapezoid is a quadrilateral with two sides (a and c) parallel.

The central median m is equal to (a+c)/2. The area of the trapezoid can be calculated by

A = hm.

A trapezoid in which the base angles are equal (and thus with equal sides b and d) is called an isosceles trapezoid. A right trapezoid has two adjacent right angles.

Last Update: 2010-12-06