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". Atlanta redirects here. ... Interstate 285 (abbreviated I-285) is a beltway interstate highway encircling Atlanta, Georgia, for 63. ...

Practical uses

Perimeter and area play a great role in today's world. 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. This article is about the physical quantity. ...

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. For equilateral polygons, P = na, where n is the number of sides and a is the measure of the side. Look up polygon in Wiktionary, the free dictionary. ... A triangle. ... This article is about the geometric shape. ... A polygon whose sides are equal (Williams 1979, pp. ...

Circles

For circles the equation is This article is about the shape and mathematical concept of circle. ...

or

• P stands for the perimeter,
• r stands for the radius
• π is the mathematical constant pi (π = 3.14159265...)
• d stands for the circle's diameter (twice the radius of a circle)

(The dot means multiply or times) This article is about an authentication, authorization, and accounting protocol. ... A mathematical constant is a quantity, usually a real number or a complex number, that arises naturally in mathematics and does not change. ... When a circles diameter is 1, its circumference is π. Pi or π is the ratio of a circles circumference to its diameter in Euclidean geometry, approximately 3. ... This article is about an authentication, authorization, and accounting protocol. ... In mathematics, multiplication is an elementary arithmetic operation. ...

In General

If r is considered to be the distance from the centre of a regular polygon to one of its vertices (or in the case of a circle, the radius), the following holds true: A regular pentagon A regular polygon is a simple polygon (a polygon which does not intersect itself anywhere) which is equiangular (all angles are equal) and equilateral (all sides have the same length). ... In geometry, a vertex (Latin: whirl, whirlpool; plural vertices) is a corner of a polygon (where two sides meet) or of a polyhedron (where three or more faces and an equal number of edges meet). ... This article is about an authentication, authorization, and accounting protocol. ...

• P stands for the perimeter,
• r stands for the radius
• A stands for the area

This article is about an authentication, authorization, and accounting protocol. ... This article is about the physical quantity. ...

See also

• Isoperimetric inequality
• Circumference
• Pythagorean Theorem
• Wetted perimeter

Isoperimetry literally means having an equal perimeter. In mathematics, isoperimetry is the general study of geometric figures having equal boundaries. ... The circumference is the distance around a closed curve. ... In mathematics, the Pythagorean theorem (AmE) or Pythagoras theorem (BrE) is a relation in Euclidean geometry among the three sides of a right triangle. ... wetted perimeter The term wetted perimeter is common in Civil Engineering and also in heat transfer applications. ...

External links

Look up Perimeter in
Wiktionary, the free dictionary.