# Length and Width of a Rectangle Calculator

Length and Width of a Rectangle Calculator is a free online tool which helps to find side length of rectangle.

## What Is Length and Width of a Rectangle Calculator?

A rectangle is a closed two-dimensional figure with four sides and four corners. The length of the opposite sides is equal and parallel to each other. Cuemath's Length and Width of a Rectangle Calculator is a free online tool that calculates the length and the width of a rectangle within a few seconds.

Note: Enter numbers upto 3 digits.

## How to Use the Length and Width of a Rectangle Calculator?

Follow the steps mentioned below to find the length and width of a rectangle.

**Step 1:**Enter the value of the area and perimeter of the rectangle in the respective input boxes.**Step 2:**Click on "**Calculate**" to find the respective length and the width of the rectangle.**Step 3:**Click on "**Reset**" to clear the fields and enter the new values.

## How to Calculate Length and Width of a Rectangle?

The formula for the area, 'A' of a rectangle whose length and width are 'l' and 'w' respectively is the product of length and width, that is, "**A = l × w**".

The formula for the perimeter, 'P' of a rectangle whose length and width are 'l' and 'w' respectively is **P = 2(l + w)**.

To calculate the length and width of a rectangle first, calculate the value of width 'w' by using the area of rectangle formula that is, '**w = A/l'**. Then substitute the value of width in the formula of the perimeter of a rectangle and simplify the value of length 'l', that is,

### P = 2 (l + A/I).

Then substitute the value of the length 'l' of the rectangle in the equation w = A/l and simplify to find the width 'w'.

Let's learn through an example how to find the length and width of a rectangle.

**Solved Example:**

If the area and the perimeter of a rectangle are 8 square units and 12 units respectively. What is the length and width of the rectangle?

**Solution:**

Substitute the values of Area in the formula 'A = l × w' and simplify to find width 'w' in the form of length 'l'.

A = l × w

8 = l × w

w = 8/l

Substitute the value of width in the formula of the perimeter of a rectangle and simplify the value of length 'l', that is, P = 2 (l + A/I).

P = 2 (l + w)

12 = 2 (l + 8/l)

6l = l^{2} + 8

l^{2} - 6l + 8 = 0

l = 4 units (or) 2 units.

Substitute the value of the length 'l' of the rectangle in the equation w = A/l and simplify to find the width 'w'.

w = A/l

If l = 4 units, then w = 8/4 = 2 units.

If l = 2 units, then w = 8/2 = 4 units.

Therefore, l = 4 units (or) 2 units

w = 2 units (or) 4 units

Now, use our online length and width of a rctangle calculator and find the length and width of a rectangle if its area and perimeter are as follows:

- Area = 80 square units, Perimeter = 36 units
- Area = 72 square units, Perimeter = 40 units