Area

You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.

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.

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

Image:Area.svg

Common equations for area:
Shape	Equation	Variables
Square	$s^2\,\!$	$s$ is the length of the side of the square.
Regular triangle	$\frac{\sqrt{3}}{4}s^2\,\!$	$s$ is the length of one side of the triangle.
Regular hexagon	$\frac{3\sqrt{3}}{2}s^2\,\!$	$s$ is the length of one side of the hexagon.
Regular octagon	$2(1+\sqrt{2})s^2\,\!$	$s$ is the length of one side of the octagon.
Any regular polygon	$\frac{1}{2}a p \,\!$	$a$ is the apothem, or the radius of an inscribed circle in the polygon, and $p$ is the perimeter of the polygon.
Any regular polygon	$\frac{P^2/n} {4 \cdot \tan(\pi/n)}\,\!$	$P$ is the Perimeter and $n$ is the number of sides.
Any regular polygon (using degree measure)	$\frac{P^2/n} {4 \cdot \tan(180^\circ/n)}\,\!$	$P$ is the Perimeter and $n$ is the number of sides.
Rectangle	$lw \,\!$	$l$ and $w$ are the lengths of the rectangle's sides (length and width).
Parallelogram (in general)	$bh\,\!$	$b$ and $h$ are the length of the base and the length of the perpendicular height, respectively.
Rhombus	$\frac{1}{2}ab$	$a$ and $b$ are the lengths of the two diagonals of the rhombus.
Triangle	$\frac{1}{2}bh \,\!$	$b$ and $h$ are the base and altitude (measured perpendicular to the base), respectively.
Triangle	$\frac{1}{2} a b \sin C\,\!$	$a$ and $b$ are any two sides, and $C$ is the angle between them.
Circle	$\pi r^2 ,\,\!$ or $\pi d^2/4 \,\!$	$r$ is the radius and $d$ the diameter.
Ellipse	$\pi ab \,\!$	$a$ and $b$ are the semi-major and semi-minor axes, respectively.
Trapezoid	$\frac{1}{2}(a+b)h \,\!$	$a$ and $b$ are the parallel sides and $h$ the distance (height) between the parallels.
Total surface area of a Cylinder	$2\pi r^2+2\pi r h \,\!$	$r$ and $h$ are the radius and height, respectively.
Lateral surface area of a cylinder	$2 \pi r h \,\!$	$r$ and $h$ are the radius and height, respectively.
Total surface area of a Cone	$\pi r (l + r) \,\!$	$r$ and $l$ are the radius and slant height, respectively.
Lateral surface area of a cone	$\pi r l \,\!$	$r$ and $l$ are the radius and slant height, respectively.
Total surface area of a Sphere	$4\pi r^2\,\!$ or $\pi d^2\,\!$	$r$ and $d$ are the radius and diameter, respectively.
Total surface area of an ellipsoid		See the article.
Circular sector	$\frac{1}{2} r^2 \theta \,\!$	$r$ and $θ$ are the radius and angle (in radians), respectively.
Square to circular area conversion	$\frac{4}{\pi} A\,\!$	$A$ is the area of the square in square units.
Circular to square area conversion	$\frac{1}{4} C\pi\,\!$	$C$ is the area of the circle in circular units.

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

External links

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

WikiDoc Help Menu

Quick Start..

Editing basics

Advanced editing

Communicating your edits

Help Videos You Can Watch

Getting Started Video

Acknowledgement and Attribution Regarding Sources of Content

Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .

Area

Units

Useful formulas

See also

External links

Acknowledgement and Attribution Regarding Sources of Content

Views

Personal tools

Search

Navigation

Help

related articles

Toolbox

In other languages