Question 517650
harriet wants to put up fencing around three sides of her rectangular yard and leave a side of 20 feet unfenced.
 If the yard has an area of 680 square feet, how many feet of fencing does she need ?
:
We're told that one side is 20 ft, by the fact that a 20 ft side is unfenced;
Assume W = 20' 
:
Area: L * W = 680
20*L = 680
L = 680/20
L = 34' is the length, (the yard is 34 by 20)
:
Perimeter: P = 2L + 2W, we only have 3 sides to fence, therefore
Fence =  2L + W 
Fence = 2(34) + 20 = 88' ft of fence required