The area of a rectangle is the result of product of its sides. The division of the area of a rectangle by one of its sides is the length of the other side. Every rectangle of constant area is limited by its hyperbola: The hyperbola y=A/x y: vertical axis x: horizontal axis A: area of the rectangle. This hyperbola is shown in the app as a shadow. The area of the rectangle is written inside the rectangle Spinners show the division of the area by the widht of the rectangle. The result is the he