Cover the orange box with three other boxes by dragging them over the orange box.[br]You will need to change the size of the other boxes. Press [b]New Example[/b] for another example.[br]Total Area Sum will change from [b][color=#ff0000]red[/color][/b] to [color=#00ff00][b]green [/b][/color]when the area of the three boxes equals the area of the orange box.