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You have 332 feet of fencing to enclose a rectangular region. What is

the maximum area?

A6889 square feet


B6885 square feet


C110,224 square feet


D27,556 square feet

Verified Answer :

6889 square feet
Letter A

Answer:

Option A is correct

The maximum area is, 6889 square feet

Step-by-step explanation:

Perimeter of a rectangle is given by:

\(P = 2(l+w)\)

where,

l is the length and w is the width of the rectangle respectively.

As per the statement:

You have 332 feet of fencing to enclose a rectangular region.

⇒\(P = 332\) feet

Then using perimeter formula:

\(332 =2(l+w)\)

Divide both side by 2 we get;

\(166 = l+w\)                

or

\(l=166-w\)                  .....[1]

Area of a rectangle(A) is given by:

\(A = lw\)                     .....[2]

Substitute the value of [1] in [2] we have;

\(A = (166-w)w\)

⇒\(A = 166w -w^2\)

We have to find the maximum area:

A quadratic equation \(y=ax^2+bx+c\) then the axis of symmetry is given by:

\(x = -\frac{b}{2a}\)

The maximum  area occurs at:

\(w = -\frac{166}{2(-1)} = \frac{166}{2} = 83\) feet

Substitute the value of w in [1] we have;

\(l = 166-83 = 83\) feet

Substitute the value of l and w in [2] we have;

\(A_{max} = 83 \cdot 83 = 6889\) square feet

therefore, the maximum area is, 6889 square feet