Measurement formulas - perimeter

The perimeter of a polygon (or any other closed curve, such as a circle) is the distance around the outside.
 perimeter is measured in linear units.

Perimeter Formulas
Shape	Formula	Variables
Square	P=4s$P=4s$	s is the length of the side of the square.
Rectangle	P=2L+2W$P=2L+2W$	L and W are the lengths of the rectangle's sides (length and width).
Triangle	a+b+c$a+b+c$	a,b$,$and c are the side lengths.
Right Triangle, with legs aand b (see  Pythagorean  Theorem )	P=a+b+a2+b2−−−−−−√$P=a+b+\sqrt{a^2+b^2}$	a and b are the lengths of the two legs of the triangle
Circle	P=C=2πr=πd$P=C=2\pi r=\pi d$	r is the radius and d is the diameter.