Question 739578
Farmer Fred wants to fence in a rectangular pasture that is bordered on one side by a river. He plans to use 7200 feet of fence to enclose the other three sides. What should the length of the pasture be if the enclosed area is to be a maximum?  
--------------
If he fences all 4 sides, the max is a square, area = 1800^2 = 3240000 sq ft.
----
Fencing 3 sides, make the width 1/2 the length --> 1800*3600 = 2x the area of the square.
--------------------
I can work it out.  If you need it email via the Thank You note.