Explanation:
Trapezoid
Trapezoid
(AmE)
Trapezium (BrE)

A Trapezoid

Type

quadrilateral

Edges and vertices

4

Area


Properties

convex

In geometry, a quadrilateral with one pair of parallel sides is
referred to as a trapezoid in American
English and as a trapezium in English outside North America. A
trapezoid with vertices ABCD is denoted ABCD or ABCD.
This article uses the term trapezoid in the sense that is current in the
United States (and sometimes in some other Englishspeaking countries).Readers
in the United Kingdom and Australia should read trapezium for each use of trapezoid in the following paragraphs. In all
other languages using a word derived from the Greek for this figure, the form
closest to trapezium (e.g. French 'trapèze', Italian 'trapezio', German
'Trapez', Russian 'трапеция')
is used.
Area
The area A of a trapezoid is given by
where a and b are the lengths of the parallel sides,
and h is the height (the perpendicular
distance between these sides) (Our solved example in mathguru.com uses this concept)
http://en.wikipedia.org/wiki/Trapezoid
The
above explanation is copied from Wikipedia, the free encyclopedia and is
remixed as allowed under the Creative Commons Attribution ShareAlike 3.0
Unported License.