Math
posted by Carly .
A rectangular enclosure is to be constructed with 800 feet of fence in order to have four sections. What should be the dimensions in order to maximize the area enclosed? What is the maximum area?

Math 
Damon
Well, I bet it turns out to be a square but anyway:
A = b c where b is breadth and c is length
2 b + 2 c = 800
so
b + c = 400
c = (400  b)
so
A = b * (400b)
A = 400 b  b^2
b^2  400 b + A = 0
where is the vertex of this parabola (I assume you do not do calculus)
b^2  400 b = A
b^2  400 b + 40,000 = A + 40,000
(b200)^2 = A + 40,00
vertex (maximum) when b = 200
then c = 400200 also = 200
just as we suspected
Respond to this Question
Similar Questions

calculus
if a farmer has 100 feet of fence and wants to make a rectangular pigpen, one side of which is along existing straight fence.What dimensions should be used in order to maximize the area of the pen? 
algebra
Mike's family wants to build a rectangular fenced backyard area for their dog. They have a 20meter length of wire fence and four posts. They can also use the 20meter straight length of the back of their house as a side of the enclosure, … 
Math
Jennifer plans to fence a rectangular area around her rectangular swimming pool. The total area enclosed by the fence, including the pool, should be 5 times the area of the pool alone. The pool is 20 feet by 17 feet. A.)What is the … 
arithematic
A horticulturalist is building a fence around a rectangular garden using the side of the building for one side of the enclosure. she has 81 feet fencing. what should be the dimensions of the enclosure be so that she can maximize the … 
Precalculus
A farmer has 1000 feet of fencing materials available to fence a rectangular pasture next to a river. If the side along the river does not need to be fenced, what dimensions maximize the enclosed area? 
College Algebra
A rectangular enclosure is to be constructed with 2,000 feet of fence in order to have four sections, as in the diagram below. What should be the dimensions in order to maximize the area enclosed? 
Math
Tiffany is constructing a fence around a rectangular tennis court. She must use 300 feet of fencing. The fence must enclose all four sides of the court. Regulation states that the length of the fence enclosure must be at least 80 feet … 
Math
A farmer has 36 feet of fence to build a pigpen. He is going to use one of the sides of his barn as a side to the rectangular enclosure. Determine a function A that represents the total area of the enclosed region. What is the maximum … 
algebra
Peter has 800 yards of fencing to enclose a rectangular area. Find the dimensions of the rectangle that maximize the enclosed area. What is the maximumâ€‹ area? 
math
A rectangular playground is to be fenced off and divided in two by another fence parallel to one side of the playground. Five hundred and forty feet of fencing is used. Find the dimensions of the playground that maximize the total …