math
posted by faye .
the area of a rectangle is 100 square inches.the perimeter of the rectangle is 40 inches.a second rectangle has the same area but a different perimeter. is the second rectangle a square?

Use calculus to prove that the minimum perimeter of a rectangle of area 100 square inches is 40 inches, and that happens when all the sides are equal, namely the rectangle is a square.
Therefore any other rectangle having a different perimeter cannot be a square. 
Separate a rectangle into 6 equal parts