Area

It has been suggested that Area (geometry)be mergedinto this article or section. (Discuss)

This article is about the physical quantity. For other uses, see Area (disambiguation).

Area is a quantity expressing the two-dimensional size of a defined part of a surface, typically a region bounded by a closed curve. The term surface area refers to the total area of the exposed surface of a 3-dimensional solid, such as the sum of the areas of the exposed sides of a polyhedron.

1 Units
2 Useful formulas
3 See also
4 External links

Units

Units for measuring surface area include:

Metric

square metre (m²) = SI derived unit

are (a) = 100 square metres (m²)

hectare (ha) = 10,000 square metres (m²)

square kilometre (km²) = 1,000,000 square metres (m²)

square megametre (Mm²) = 1012 square metres

square foot = 144 square inches = 0.09290304 square metres (m²)

square yard = 9 square feet = 0.83612736 square metres (m²)

square perch = 30.25 square yards = 25.2928526 square metres (m²)

acre = 160 square perches or 4,840 square yards or 43,560 square feet = 4046.8564224 square metres (m²)

square mile = 640 acres = 2.5899881103 square kilometres (km²)

Useful formulas

Common equationsfor area: Shape Equation Variables Squares is the length of the side of the square. Regular triangles is the length of one side of the triangle. Regular hexagons is the length of one side of the hexagon. Regular octagons is the length of one side of the octagon. Any regular polygon a is the apothem, or the radius of an inscribed circle in the polygon, and p is the perimeter of the polygon. Any regular polygon P is the Perimeter and n is the number of sides. Any regular polygon (using degree measure) P is the Perimeter and n is the number of sides. Rectanglel and w are the lengths of the rectangle's sides (length and width). Parallelogram(in general) b and h are the length of the base and the length of the perpendicular height, respectively. Rhombusa and b are the lengths of the two diagonalsof the rhombus. Triangleb and h are the baseand altitude(measured perpendicular to the base), respectively. Trianglea and b are any two sides, and C is the angle between them. Circleor r is the radius and d the diameter. Ellipsea and b are the semi-majorand semi-minoraxes, respectively. Trapezoida and b are the parallel sides and h the distance (height) between the parallels. Total surface area of a Cylinderr and h are the radius and height, respectively. Lateral surface area of a cylinder r and h are the radius and height, respectively. Total surface area of a Coner and l are the radius and slant height, respectively. Lateral surface area of a cone r and l are the radius and slant height, respectively. Total surface area of a Sphereor r and d are the radius and diameter, respectively. Total surface area of an ellipsoid See the article. Circular sectorr and θ are the radius and angle (in radians), respectively. Squareto circular area conversion A is the area of the squarein square units. Circularto square area conversion C is the area of the circlein circular units.

All of the above calculations show how to find the area of many shapes.