Question

Graham has enough fencing to enclose a rectangular garden with a perimeter of 140 feet. If the width of his garden is 20 feet less than the length, what is the width of the garden? A: 20 feet B: 45 feet C: 25 feet D: 40 feet

Answer 1

Given

• perimeter of a rectangle is 140 ft
• length is 20 ft more than width

Find

• the width of the rectangle

Solution

The formula for the perimeter of a rectangle in terms of length and width is

... P = 2(L + W)

Since the length is 20 ft more than the width, we can use W+20 for the length and W for the width. Filling in the given information, we have

... 140 = 2((W+20) +W)

... 140 = 4W +40 . . . . . simplify

... 100 = 4W . . . . . . . . . subtract 40

... 25 = W . . . . . . . . . . . divide by 4

The appropriate choice is ...

... C: 25 feet