Find the dimensions of the rectangular corral split into #2# pens of the same size producing the greatest possible enclosed area given #300# feet of fencing?

1 Answer
Dec 2, 2017

Total rectangle = #42.9 xx 85.8#
Area = #3680#

Explanation:

First, the "maximum" area is irrelevant - it can only be the product of the sides, which is the same for any rectangular perimeter.

In this case it is really just two identical rectangles with a shared side. SO, if we call them "X x Y" rectangles, the overall fence used is #3X + 4Y = 300#. The area of the combined space is #X xx 2Y#, which is the same area for any constant sum of X and Y.

Because the relative values do not affect the area, we can take a square as a reasonable geometry for the individual sections. In that case, #X = Y#, so the overall fence use is #3X + 4X = 300#
#X = 300/7 = 42.9 = Y#
The total area is #X xx 2Y = 42.9 xx 42.9 xx 2 = 3680#
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