Surface

surface or surface is the dimension of one surface. By metonymy, one often indicates this dimension by the term "surfaces" itself (for example, one speaks about the "surface of a square" whereas it would be necessary to speak about its surface).

The term surface (of bottom Latin will aera space plane) is used in .

The term surface is used mainly for grounds (surface of a garden, of a field) and expresses themselves (in international system of units) in (m²).

Metric measures:

• are (1 A = 100 m²)
• hectare (1 ha = 10 000 m²)
• square kilometre (1 km² = 1 000 000 m²)

Other measurements:

• acre or arpent

Calculation of the surface

The calculation of surface is a broad active field of mathematics ofsurface of usual surfaces until .

The calculation of the surface for elementary geometrical figures is simple. more complex can cut out in , and one can then calculate the surface of each triangle:

in Euclidean geometry, the surface of a triangle is the product length of its base by its height, divided by two.

When it acts of a surface delimited by a curve, one makes an approximation of this curve by a polygon and one applies the method above to have an approximation of the surface; if this curve can be expressed by one , it is enough to calculate it of this function.

Examples

• Square on side a: has²
  

Thus the surface is worth AD X AB = BA X BC = BC X CD = DA X cd.

• Rectangle of width L and length L: L X L
  

Thus the surface is worth AD X AB = BA X BC = BC X CD = DA X cd.

• Basic triangle B and height H: (B X H)/2
  

Thus the surface is worth (MINOR ROAD X AB)/2

• Losangle of diagonal has and b: 1/2 X have X B
  

Thus the surface is worth 1/2 X AC X data base

• Basic parallelogram B and height H: B X H
  

Thus the surface is worth AB X AH = cd. X AH

• Trapezoid of small base B, great base B and height H: 1/2 X (B + B) X H
  

Thus the surface is worth 1/2 X (AB + cd.) X AH

• Circle of radius R: ? X R²
  

• Ellipse of semi-axis has and b: X B X has?
  

See too

• Specific surface