Just use your right angled triangle formula.
A=

Plug n chug
A=

A=71.5
694.407 and there is a cap over the three numbers at the very end
The answer to the question would be 3.5
First, you could see the amount of fence he could buy, or 144/6, which would be 24, so Mr. North can buy 24 yards of fencing.
So now to find the possible plans, we know that there are four sides, but the width and the length occur twice since it's a rectangle.
So since we know that, we can just split 24 in half to find the possibilities for one of the width sides and one of the length sides, if that makes any sense. 24/2 = 12.
So now, you could say some possibilities are length = 6 and width = 6, or length = 4 and width = 8.
And now, to consider which plan would be the best, it would probably be a 6x6 design, because it gives the biggest area to the vegetable garden, and is easy to move around.
width = 6
length = 6
area = 36 square yards (6×6)
perimeter = 24 yards (6+6+6+6)
You can sole it because I believe in you