Perimeter
Path that surrounds an area / From Wikipedia, the free encyclopedia
For other uses, see Perimeter (disambiguation).
A perimeter is a closed path that encompasses, surrounds, or outlines either a two dimensional shape or a one-dimensional length. The perimeter of a circle or an ellipse is called its circumference.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/b/b0/Perimiters.svg/250px-Perimiters.svg.png)
Calculating the perimeter has several practical applications. A calculated perimeter is the length of fence required to surround a yard or garden. The perimeter of a wheel/circle (its circumference) describes how far it will roll in one revolution. Similarly, the amount of string wound around a spool is related to the spool's perimeter; if the length of the string was exact, it would equal the perimeter.