Question 1131035
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A rectangle of a given perimeter has a maximum area if and only if it is a square.


For the proof,  see the lesson

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/A-rectangle-with-the-given-perimeter-which-has-the-maximal-area-is-a-square.lesson>A rectangle with a given perimeter which has the maximal area is a square</A>

in this site.


<pre>
So, in your case a rectangle must be a square with the side length of  312/4 = 78 feet.      <U>Answer</U>
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