Perimeter
From Free net encyclopedia
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." Perimeter can be calculated for any two dimensional object, with the right formula.
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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.
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 <math>P=a+b+c</math>, where <math>a</math>, <math>b</math> and <math>c</math> stand for each side of it. For quadrilaterals the equation is <math>P=a+b+c+d</math>. For equilateral polygons, <math>P=na</math>, where n is the number of sides and a is the side length.
Circles
For circles the equation is
- <math>
P = 2 \cdot \pi \cdot r
</math> or
- <math>
P = d \cdot \pi
</math>
- <math>P</math> stands for the perimter,
- <math>r</math> stands for the radius
- <math>\pi</math> is the mathematical constant pi (<math>\pi=3,14159265...</math>)
- <math>d</math> stands for the circle's diameter
See also
See also:
ca:Perímetre de:Umfang es:Perímetro fr:Périmètre it:Perimetro pt:Perímetro nl:Perimeter ru:Периметр simple:Perimeter zh:周界