Area (symbolized A ) is a two-dimensional quantity representing amount or extent of surface. The standard unit of area in the International System of Units (SI) is the meter squared (m2). Area is usually measured or defined on a flat surface, also called a Euclidean plane, or on a spherical surface.
Every unit of length has a corresponding unit of area, namely the area of a square with the given side length. Thus areas can be measured in square meters (m2), square centimeters (cm2), square millimeters (mm2), square kilometers (km2), square feet (ft2), square yards (yd2), square miles (mi2), and so forth. Algebraically, these units can be thought of as the squares of the corresponding length units.