"Area" is a quantity that expresses the extent of a two-dimensional surface or shape, or planar lamina, in the plane.
Applicable units are those of quantitykind:Area
http://en.wikipedia.org/wiki/Area
"Area" is a quantity that expresses the extent of a two-dimensional surface or shape, or planar lamina, in the plane.
$A = \int\int dxdy$, where $x$ and $y$ are cartesian coordinates.
http://www.iso.org/iso/catalogue_detail?csnumber=43012