The perimeter P of a rectangle is given by the formula

P = 2 × L + 2 × W

where L and W are the length and width, respectively, of the of the rectangle.
## How to Find the Perimeter of a Rectangle? Examples with Solutions

Example 1

Find the perimeter of a rectangle of length 20 meters and width 10 meters.

Solution to Example 1

Both the length L and the width W have the same units. We need to substitute L and W by their values in the formula of the perimeter as follows

P = 2 L + 2 W = 2×20 + 2×10 = 40 + 20 = 60 meters

Example 2

The length of a rectangle is 12.5 meters and its width is 800 centimeters. Find the perimeter of the rectangle in centimeters.

Solution to Example 2

Since we need to find the perimeter in centimeters, we first need to convert the length in centimeters.

L = 12.5 meters = 12.5 × 100 = 1250 centimeters

The perimeter P of the rectangle is given by

P = 2× L + 2 × W = 2× 1250 + 2× 800 = 4100 centimeters

Example 3

The length of a rectangle is 240 meters and its width is the third of its length. Find the perimeter of this rectangle.

Solution to Example 3

We first need to find width W of the rectangle given its length L = 240 meters.

W = (1/3) × L = (1/3) × 240 = 1 × 240 / 3 = 80 meters

The perimeter P of the rectangle is given by

P = 2× L + 2 × W = 2× 240 + 2× 80 = 640 meters

Example 4

The width of a rectangle is 1200 meters and its length is 500 meters longer that its width. Find the perimeter of this rectangle.

Solution to Example 4

We first need to find length L of the rectangle given its width W = 1200 meters.

L = 500 + W = 500 + 1200 = 1700 meters

The perimeter P of the rectangle is calculated as follows

P = 2× L + 2 × W = 2× 1700 + 2× 1200 = 5800 meters

Example 5

A large rectangular field of length 500 meters and width 400 meters is to be enclosed along its perimeter by a fence. What is the total cost of the fence if the rate is $2 per meter?

Solution to Example 5

We need to find the perimeter

P = 2 L + 2 W = 2×500 + 2×400 = 1000 + 800 = 1800 meters

Every meter costs $2 to fence. Hence the total C cost to fence this field is given by

C = P × 2 = 1800 × 2 = $3600

### More References and links

Perimeter Questions With Answers and Solutions

Area, Perimeter and Diagonal of a Rectangle - Calculator .

Length and Width of Rectangle - Geometry Calculator.