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Area

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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.

Contents

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 (m²)
US & Imperial Units
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 equations for area:
Shape Equation Variables
Square Failed to parse (Missing texvc executable; please see math/README to configure.): s^2\,\! Failed to parse (Missing texvc executable; please see math/README to configure.): s
is the length of the side of the square.
Regular triangle Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{\sqrt{3}}{4}s^2\,\! Failed to parse (Missing texvc executable; please see math/README to configure.): s
is the length of one side of the triangle.
Regular hexagon Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{3\sqrt{3}}{2}s^2\,\! Failed to parse (Missing texvc executable; please see math/README to configure.): s
is the length of one side of the hexagon.
Regular octagon Failed to parse (Missing texvc executable; please see math/README to configure.): 2(1+\sqrt{2})s^2\,\! Failed to parse (Missing texvc executable; please see math/README to configure.): s
is the length of one side of the octagon.
Any regular polygon Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{1}{2}a p \,\! Failed to parse (Missing texvc executable; please see math/README to configure.): a
is the apothem, or the radius of an inscribed circle in the polygon, and Failed to parse (Missing texvc executable; please see math/README to configure.): p
is the perimeter of the polygon.
Any regular polygon Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{P^2/n} {4 \cdot tan(\pi/n)}\,\! Failed to parse (Missing texvc executable; please see math/README to configure.): P
     is the Perimeter and Failed to parse (Missing texvc executable; please see math/README to configure.): n
is the number of sides.
Any regular polygon (using degree measure) Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{P^2/n} {4 \cdot tan(180^\circ/n)}\,\! Failed to parse (Missing texvc executable; please see math/README to configure.): P
is the Perimeter and Failed to parse (Missing texvc executable; please see math/README to configure.): n
is the number of sides.
Rectangle Failed to parse (Missing texvc executable; please see math/README to configure.): l \cdot w \,\! Failed to parse (Missing texvc executable; please see math/README to configure.): l
and Failed to parse (Missing texvc executable; please see math/README to configure.): w
are the lengths of the rectangle's sides (length and width).
Parallelogram (in general) Failed to parse (Missing texvc executable; please see math/README to configure.): b \cdot h\,\! Failed to parse (Missing texvc executable; please see math/README to configure.): b
and Failed to parse (Missing texvc executable; please see math/README to configure.): h
are the length of the base and the length of the perpendicular height, respectively.
Rhombus Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{1}{2}ab Failed to parse (Missing texvc executable; please see math/README to configure.): a
and Failed to parse (Missing texvc executable; please see math/README to configure.): b
are the lengths of the two diagonals of the rhombus.
Triangle Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{1}{2}b \cdot h \,\! Failed to parse (Missing texvc executable; please see math/README to configure.): b
and Failed to parse (Missing texvc executable; please see math/README to configure.): h
are the base and altitude (measured perpendicular to the base), respectively.
Triangle Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{1}{2}\cdot a \cdot b \cdot sinC\,\! Failed to parse (Missing texvc executable; please see math/README to configure.): a
and Failed to parse (Missing texvc executable; please see math/README to configure.): b
are any two sides, and Failed to parse (Missing texvc executable; please see math/README to configure.): C
is the angle between them.
Circle Failed to parse (Missing texvc executable; please see math/README to configure.): \pi r^2 \,\!

, or Failed to parse (Missing texvc executable; please see math/README to configure.): \pi d^2/4 \,\!

Failed to parse (Missing texvc executable; please see math/README to configure.): r
is the radius and Failed to parse (Missing texvc executable; please see math/README to configure.): d
the diameter.
Ellipse Failed to parse (Missing texvc executable; please see math/README to configure.): \pi ab \,\! Failed to parse (Missing texvc executable; please see math/README to configure.): a
and Failed to parse (Missing texvc executable; please see math/README to configure.): b
are the semi-major and semi-minor axes, respectively.
Trapezoid Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{1}{2}(a+b)h \,\! Failed to parse (Missing texvc executable; please see math/README to configure.): a
and Failed to parse (Missing texvc executable; please see math/README to configure.): b
are the parallel sides and Failed to parse (Missing texvc executable; please see math/README to configure.): h
the distance (height) between the parallels.
Total surface area of a Cylinder Failed to parse (Missing texvc executable; please see math/README to configure.): 2\pi r^2+2\pi r h \,\! Failed to parse (Missing texvc executable; please see math/README to configure.): r
and Failed to parse (Missing texvc executable; please see math/README to configure.): h
are the radius and height, respectively.
Lateral surface area of a cylinder Failed to parse (Missing texvc executable; please see math/README to configure.): 2 \pi r h \,\! Failed to parse (Missing texvc executable; please see math/README to configure.): r
and Failed to parse (Missing texvc executable; please see math/README to configure.): h
are the radius and height, respectively.
Total surface area of a Cone Failed to parse (Missing texvc executable; please see math/README to configure.): \pi r (l + r) \,\! Failed to parse (Missing texvc executable; please see math/README to configure.): r
and Failed to parse (Missing texvc executable; please see math/README to configure.): l
are the radius and slant height, respectively.
Lateral surface area of a cone Failed to parse (Missing texvc executable; please see math/README to configure.): \pi r l \,\! Failed to parse (Missing texvc executable; please see math/README to configure.): r
and Failed to parse (Missing texvc executable; please see math/README to configure.): l
are the radius and slant height, respectively.
Total surface area of a Sphere Failed to parse (Missing texvc executable; please see math/README to configure.): 4\pi r^2\,\!
or Failed to parse (Missing texvc executable; please see math/README to configure.): \pi d^2\,\!
Failed to parse (Missing texvc executable; please see math/README to configure.): r
and Failed to parse (Missing texvc executable; please see math/README to configure.): d
are the radius and diameter, respectively.
Total surface area of an ellipsoid   See the article.
Circular sector Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{1}{2} r^2 \theta \,\! Failed to parse (Missing texvc executable; please see math/README to configure.): r
and Failed to parse (Missing texvc executable; please see math/README to configure.): \theta
are the radius and angle (in radians), respectively.
Square to circular area conversion Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{4}{\pi} A\,\! Failed to parse (Missing texvc executable; please see math/README to configure.): A
is the area of the square in square units.
Circular to square area conversion Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{1}{4} C\pi\,\! Failed to parse (Missing texvc executable; please see math/README to configure.): C
is the area of the circle in circular units.

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

See also

External links

Look up Area in
Wiktionary, the free dictionary.

als:Fläche ar:مساحة arc:ܫܛܝܚܘܬܐ zh-min-nan:Biān-chek be-x-old:Плошча bg:Площ ca:Àrea cs:Obsah cy:Arwynebedd da:Areal de:Flächeninhalt et:Pindala el:Έκταση es:Área (geometría) eo:Areo eu:Azalera fa:مساحت fo:Vídd fr:Superficie gd:Farsaingeachd gu:ક્ષેત્રફળ ko:넓이 hr:Površina io:Areo ilo:Kalawa id:Luas is:Flatarmál it:Area he:שטח ka:ფართობი la:Area lv:Platība lb:Fläch lt:Plotas li:Oppervlak ln:Etando hu:Terület mk:Плоштина mg:Velarantany ml:വിസ്തീര്‍ണ്ണം ms:Keluasan nl:Oppervlakte ja:面積 no:Areal nn:Flatevidd oc:Superfícia nds:Flach pt:Área ro:Suprafaţă qu:Hallka k'iti k'anchar ru:Площадь sco:Area simple:Area sl:Površina fi:Pinta-ala sv:Ytmått tl:Lawak ta:பரப்பளவு th:พื้นที่ vi:Diện tích tr:Alan uk:Площа yi:שטח zh-yue:面積

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