The area of a rectangle is the amount of space taken up by the rectangle. To find the area of a rectangle, we simply have to multiply its length by its width. Hence, the formula to find the area of a rectangle is:

 

$$\LARGE{A = lw}$$

where \({l}\) is the length and \({w}\) is the width

 

Let's apply this formula by taking a look at a few examples.

Example 1: What is the area of the rectangle below?

rectangle that is 19 feet long and 13 feet wide

Here we have a rectangle that is 19 feet long and 13 feet wide. Therefore, our length is 19 ft and width is 13 ft.

Remember that the area of a rectangle is the length times the width. Applying the formula, we get

$$\eqalign{
   A & = lw  \cr 
  &  = \left( {19} \right)\left( {13} \right)  \cr 
  &  = 247 \cr} $$

Don't forget, we always write the area as units squared. So, the area of the rectangle above is 247 feet squared or 247 ft2.


 

Example 2: The area of a rectangular yard is 120 m2. If the width is 8 meters, find the length. 

Since we know the area,  \(A=120\), and the width, \(w=8\), this makes it easy for us to find the length using the formula

$$\eqalign{
   A& = lw  \cr 
   120 &= \left( l \right)\left( 8 \right)  \cr 
   120 &= 8l  \cr 
  {{120} \over 8} &= {{8l} \over 8}  \cr 
   15& = l \cr} $$

Therefore, the length of the rectangular yard is 15 meters