The perimeter of a rectangle is 70 feet. The length is 5 feet more than the width. Find the length and the width.

Question

The perimeter of a rectangle is 70 feet. The length is 5 feet more than the width. Find the length and the width. 

Answer 1

Hy Nancy,

 

 

As you probably know the perimeter of a rectangle is given by the formula 2l + 2w where the length and width are represented by the letters l and w .

 

In our case,

 

l = w + 5 ( since the problem states that the length is 5 more than the width)

 

70 = 2 (w+5) + 2w

 

70 = 2w + 10 + 2w

 

4w = 60 

 

w = 15

 

l = 20

 

Our length is going to be 20 ft and our width 15 ft.

 

 

Answer 2

Hi Nancy,

 

The perimeter is the sum of the two lengths and the two widths.

 

So if we let L = the length and W = the width, 2L + 2W = 70

 

If the length is 5 feet more than the width, then L = W + 5

 

Substitute W + 5 for L in the first equation--> 2(W + 5) + 2W = 70

 

2W + 10 + 2W = 70

 

4W + 10 = 70

 

4W = 60

 

W = 15

So L = 20

 

Plug these numbers back in to the question to make sure that they work.

 

Have fun.

 

Dan