Define a new class called GraphicObject, and make it a subclass of NSObject. Define instance variables in your new class as follows: int fillColor; // 32-bit color BOOL filled; // Is the object...

Define a new class called GraphicObject, and make it a subclass of NSObject. Define instance variables in your new class as follows: int fillColor; // 32-bit color BOOL filled; // Is the object filled? int lineColor; // 32-bit line color Write methods to set and retrieve the variables defined previously. Make the Rectangle class a subclass of GraphicObject. Define new classes, Circle and Triangle, which are also subclasses of GraphicObject.Write methods to set and retrieve the various parameters for these objects and also to calculate the circle’s circumference and area, and the triangle’s perimeter and area.