The perimeter is 72 feet and the length is 20 feet. What is the width of the rectangle?

Question

Please solve this problem for me. 

Answer 1

Set up a simple equation to solve this.  Since the perimeter of the rectangle is a sum of all the sides and we know at least two of the sides are 20 feet, we can set it up like this: (2*20) + 2x = 72. (The 2x is because the unknown sides have to be the same length).  Now do some algebra on it and solve for x:

 

40 + 2x = 72

 

Subtract 40 from both sides:

 

2x = 32

 

Divide both sides by 2:

 

x = 16.

 

Check your answer by finding the perimeter of a 16x20 rectangle:

 

(16*2) + (20*2) = 72 feet.

 

So we know for sure that 16 feet is the correct answer.