# Perimeter

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Perimeter

The perimeter is the distance around a given two-dimensional object. The word perimeter is a Greek root meaning measure around, or literally "around-measure".

Practical uses

Calculations of perimeter and area have considerable practical applications. Perimeter is used in calculating the border of an object such as a yard or flowerbed when a fence or other border is being installed around the edges. Area is used when all the area inside of a perimeter is being covered with something, such as a yard being covered with sod or fertilizer.

In military usage, the term perimeter defines a geographic area of importance, such as a physical installation or defensive work, but can also refer to a theoretical construct such as an all-round defense formed by a small group of soldiers, the purpose of which is mutual protection of each other rather than defence of actual territory.

Formulas

Polygons

As a general rule, the perimeter of a polygon can always be calculated by adding all the length of the sides together.So, the formula for triangles is $P=a+b+c$, where $a$, $b$ and $c$ stand for each side of it. For quadrilaterals the equation is $P=a+b+c+d$ or $P=a+b+a+b$. For equilateral polygons, $P=na$, where "n" is the number of sides and "a" is the measure of the side.

Circles

For circles the equation is: $P = 2 pi r$or: $P = pi d$

where $P$ is the perimeter, $r$ is the circle's radius, $pi$ is the mathematical constant pi, and $d$ is the circle's diameter.

In general

If r is considered to be the distance from the center of a regular polygon to one of its vertices (or in the case of a circle, the radius), the following holds true:: $P = frac\left\{dA\right\}\left\{dr\right\}$
* $P$ stands for the perimeter,
* $d$ stands for the differential operator
* $r$ stands for the radius
* $A$ stands for the area

* Isoperimetric inequality
* Circumference
* Pythagorean Theorem
* Wetted perimeter

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• Perimeter — Основная информация Жанры Brutal death metal Deathcore Tech …   Википедия

• Perimeter — Éditeur 1C Développeur K D Lab Date de sortie  France : 21 mai 2004 …   Wikipédia en Français

• perimeter — unlike parameter, is rarely used in figurative meanings, but occasional uses are found, usually in the context of broader metaphors: • The perimeter of her own life was shrinking J. Urquhart, CanE 1986 …   Modern English usage

• Perimeter — Per*im e*ter, n. [Gr. ?; ? around + ? measure: cf. F. p[ e]rim[ e]tre.] 1. (Geom.) The outer boundary of a body or figure, or the sum of all the sides. [1913 Webster] 2. An instrument for determining the extent and shape of the field of vision.… …   The Collaborative International Dictionary of English

• Perimeter — (v. gr.), der Umfang, bes. von Figuren gebraucht, welche von geraden Linien begrenzt werden, im Gegensatz zu Peripherie (s.d.); daher Perimetrisch (Perimetral), dem Umfang nach …   Pierer's Universal-Lexikon

• Perimeter — (griech.), ziemlich veraltetes Fremdwort für Umfang (s. d.); auch ein Instrument zur Messung des Gesichtsfeldes. Am häufigsten wird das von Aubert und Foerster angegebene P. benutzt. Näheres s. Tafel »Augenuntersuchung«, S. IV. Vgl. Ole Bull,… …   Meyers Großes Konversations-Lexikon

• Perimeter — Perimĕter (grch.), der Umfang von geradlinigen Figuren; perimētrisch, perimetrāl, dem Umfang nach …   Kleines Konversations-Lexikon

• Perimeter — Perimeter, griech., in der Mathematik der Umfang einer geradlinigen Figur …   Herders Conversations-Lexikon

• perimeter — I noun ambit, border, borderline, boundary, bounds, brink, circuit, circumference, compass, configuration, confines, contour, curb, delineation, edge, enclosure, frontier, girdle, limit, limitations, margin, outline, outside edge, pale, periphery …   Law dictionary

• perimeter — (n.) 1590s, line around a figure or surface, from L. perimetros, from Gk. perimetros circumference, from peri around (see PERI (Cf. peri )) + metron measure (see METER (Cf. meter) (n.2)). Military sense of …   Etymology dictionary

• perimeter — *circumference, periphery, circuit, compass …   New Dictionary of Synonyms