Maximum Area of a Rectangle if Fixed Perimeter

If a rectangle has a fixed perimeter, find for what dimensions the rectangle will have maximum area.
  • Change the shape of the rectangle by moving the blue point.
  • The red point in the first quadrant has an -coordinate equal to the blue side of the rectangle and a -coordinate equal to the area of the rectangle. Observe the way the point is moving to find when the rectangle will have maximum area.
  • Enter the function that will describe the area as a function of the blue side () of the rectangle.