Answer:
length = 99 yards
Explanation:
the perimeter (P) of a rectangle is calculated as
P = 2(l + w) ← l is the length and w the width
given P = 356 and w = 79 , then
356 = 2(l + 79) ← divide both sides by 2
178 = l + 79 ( subtract 79 from both sides )
99 = l
the length of the field is 99 yards