static void Main(string[] args) { Shape[] myShapes = new Shape[3]; myShapes[0] = new Shape(); myShapes[1] = new Circle() {Radius = 10}; myShapes[2] = new Square(); foreach (Shape shape in myShapes) { Console.WriteLine(shape.Draw()); if (shape is Circle) { Console.WriteLine("\t The radius is {0}", ((Circle)shape).Radius); } } Console.ReadLine(); }