Question 1031061
Hi there,
Make length = x
Width = x - 4
Area of rectangle 
= width x length
252 = (x - 4) * x  (* times)
x^2 - 4x = 252
x^2 - 4x - 252 = 0
(x - 18)(x + 14) = 0
x + 14 = 0
x = -14 (Disregard as -ve value)
x - 18 = 0
x = 18
Length = 18 feet
Width = 14 feet.
Hope this helps :-)