Measure of a two-dimensional closed surface.
- Synonym for surface area.
- The term surface area is generally used in the case of large surfaces.
- Area is a quantity that is almost always expressed using denominate numbers.
- The side c of a square measures 10 cm.
The area A of this square is 100 cm², because: A = c × c = 10 × 10 = 100.
- A rectangle measures 8 cm long (a) and 6 cm wide (b).
The area A of this rectangle is 48 cm², because: A = a × b = 8 × 6 = 48.
- The radius r of a circle measures 10 cm.
The area A of this circle is 100π cm², because: A = πr² = π × 10² = 100π.
The basic unit of area in the International System of Units (SI) is the square metre, noted as m².
The relationship among the different units of area are:
|0.000 001||0.0001||0.01||1||100||10 000||1 000 000|
The area of a figure is a measurement, so we should say the area of a square or the area of the surface of a square.