Question 167972
I happen to know that a rectagle of a 
certain perimeter has the largest area 
when it is a square. I'll prove it
If the perimeter is {{{72}}}, and it is a 
square, each side is {{{72/4 = 18}}}
The area of the square is {{{18*18 = 324}}}
Now suppose it's not a square, but slightly
off like 17.9 x 18.1 That still
makes the perimeter 72.
{{{17.9*18.1 = 323.99}}}, so 
{{{324}}} is the maximum area which occurs when
the rectangle is an 18 x 18 square