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
