A circle will will give the greatest square foot area for a given circumference.
Pi x dia = 150
Divide bothside by pi (3.14 will work)
Dia = 47.77; Radius = 23.885
Pi (radius squared) = area
3.14 x 23.885 x 23.885 =1791.35 square feet.
If you need to make it a rectangle, a square will yield...