
Bill K. answered 10/06/15
Tutor
5.0
(247)
Ivy League College Prep
Let Length = L = 2 + 2W
Area = 312
Area = length x width
Area = length x width
312 = (2+2W)W = 2W + 2W2
divide by 2 and rearrange
W2 + W - 156 = 0
quadratic has two solutions
(W-12)*(W+13) = 0
W = 12 is one solution and L = 2+2W = 26 yards
Use Pythagorean Theorem to find the diagonal as sqrt(122 + 262) = 28.64 yds