SOLUTION: The length of a rectangle is 4 cm longer than the width. If the perimeter of the rectangle is 20 centimeters, what is the area of the rectangle?
Question 315539: The length of a rectangle is 4 cm longer than the width. If the perimeter of the rectangle is 20 centimeters, what is the area of the rectangle? Answer by moshiz08(60) (Show Source):
You can put this solution on YOUR website! Length is 4 more than width, that is .
Perimeter is the sum of the four sides. Since we have a rectangle, opposite sides have the same length. So two of the sides have length L and the other two are the width W. So .
We are given that , so . We can substitute our equation for L in here now:
Distribute the 2 to get
Subtract 8 from both sides to get
Dividing by 4 gives
The width is 3. The length is 4 more than the width, which means the length is 7.
Thus, we have a 3 x 7 rectangle which has an area of 21 square centimeters.
We checked that the length of 7 is 4 more than the width 3. Now check to make sure that indeed the perimeter is 20, and then you have your answer.
