diagonal of a square = sqrt(2) times S ( side )
half the diagonal = 6 yards so the full diagonal would be 12 yards
so you get
12 = sqrt(2) * S
S = 12/sqrt(2) = 8.485 yards
area = S^2
8.485^2 = 71.995
round answer to 72 square yards
Answer is provided in the image attached.
