Editing Area (section)

====Rectangles====
[[File:RectangleLengthWidth.svg|thumb|right|upright|alt=A rectangle with length and width labelled|The area of this rectangle is&nbsp;{{mvar|lw}}.]]
The most basic area formula is the formula for the area of a [[rectangle]]. Given a rectangle with length {{mvar|l}} and width {{mvar|w}}, the formula for the area is:<ref name=AF>{{cite web |url=http://www.math.com/tables/geometry/areas.htm |title=Area Formulas |publisher=Math.com |access-date=2 July 2012 |url-status=live |archive-url=https://web.archive.org/web/20120702135710/http://www.math.com/tables/geometry/areas.htm |archive-date=2 July 2012}}</ref>

:{{bigmath|''A'' {{=}} ''lw''}} &nbsp;(rectangle).
That is, the area of the rectangle is the length multiplied by the width.  As a special case, as {{math|''l'' {{=}} ''w''}} in the case of a square, the area of a square with side length {{mvar|s}} is given by the formula:<ref name=MathWorld/><ref name=AF/>
:{{bigmath|''A'' {{=}} ''s''<sup>2</sup>}} &nbsp;(square).

The formula for the area of a rectangle follows directly from the basic properties of area, and is sometimes taken as a [[definition]] or [[axiom]].  On the other hand, if [[geometry]] is developed before [[arithmetic]], this formula can be used to define [[multiplication]] of [[real number]]s.