Perimeter is a mathematical concept that measures the total length around the outside of a shape. It is the distance around the edge of a 2D shape. The perimeter of a shape is defined as the total distance around the shape, and it is the length of the outline or boundary of any two-dimensional geometric shape. The perimeter of a shape is determined by adding the length of all the sides and edges enclosing the shape. The perimeter of a circle or an ellipse is called its circumference. Calculating the perimeter has several practical applications. For example, a calculated perimeter is the length of fence required to surround a yard or garden. Similarly, the perimeter of a wheel/circle (its circumference) describes how far it will roll in one revolution. The amount of string wound around a spool is related to the spools perimeter.

To calculate the perimeter of a shape, you add together the lengths of all the sides. The perimeter of a shape is always calculated by adding up the length of each of the sides. The perimeter of a regular polygon is the sum of all its sides, which is equal to the number of sides multiplied by the length of one side. The perimeter of a square is easy to calculate if one side is given as all sides are the same length; the perimeter of a square with side length 5 cm is 20 cm, because 5 x 4 = 20. The perimeter of a rectangle can be calculated by adding the length and width together and doubling it.

Formulas for calculating the perimeter of different shapes are available. For example, the formula for the perimeter of a circle is 2πr, where r is the radius of the circle. The formula for the perimeter of a rectangle is 2(l + w), where l is the length and w is the width of the rectangle.

In summary, perimeter is the total length of the boundary of any closed shape. It is measured in linear units of measurement like centimeters, meters, inches, or feet. The perimeter of a shape is calculated by adding up the length of all the sides enclosing the shape. Formulas are available to calculate the perimeter of different shapes.