**To find the perimeter of any shape, the outside edges of the shape should be added together.** The perimeter is defined as the distance that is around the outside of a two dimensional shape.

There are certain formulas that can make finding the perimeter of different shapes easier and more efficient. To find the perimeter of a triangle, all three sides should be added together. To find the perimeter of a square, the length of one side can be multiplied by 4. To find the perimeter of a rectangle, the length and width can be added together and multiplied by 2. Since a quadrilateral does not have sides that are equal to each other, each of the sides should be added together individually.

The perimeter of a circle is called the circumference. The radius of a circle is half of a line through the middle of the circle. To find the circumference, the radius should be multiplied by pi and then multiplied by 2. A sector is a section of a circle that is defined by degrees in radians. To find the perimeter of a sector, the angle of the sector should be added to 2 and should be multiplied by the radius of the circle.