How do you get the perimeter of a rectangle with an area of 4000 sq yards and a length of 80 yards?

Area = Length * Breadth

So 4000 = 80 * Breadth so that Breadth = 4000/80 = 50 yards.

Then perimeter = 2*L + 2*B = 2*80 + 2*50 = 160+100 = 260 yards.