Archive | March, 2010

What is the greatest possible area of this rectangle?

25 Mar
The perimeter of a rectangle is 30cm. What is the greatest possible area of this rectangle? (This was a P6 CA1 Revision Question)
Mr Prasad spotted an error in my solution. Thank You Mr Prasad.
My comment : When doing this question, I was thinking of not choosing numbers with decimals.  But looking back now, I can’t find any reason for doing that. I gave the solution as 56 sq.cm.
In general, given the perimeter, the area will be greater as it approaches the shape of a square but reaches its maximum when it is a square.
I quote Mr Prasad: “For a given perimeter , maximum area is possible when the shape of rectangle is  square .”
Hence greatest possible area is 56.25 sq.cm ( 7.5 X 7.5)