Polymorphism (C#)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create some objects
            DrawingObject[] dObj = new DrawingObject[2];

            dObj[0] = new Circle(50);
            dObj[1] = new Square(10,10);

            foreach (DrawingObject drawObj in dObj)
            {
                switch (drawObj.GetType().Name)
                {
                    case "Circle":
                        Circle circle = (Circle)drawObj;
                        Console.WriteLine (string.Format("I'm a {0} with area of {1} derived from {2}", circle.Draw(), circle.Area(), circle.DrawBase()) );
                        break;
                    case "Square":
                        Square square = (Square)drawObj;
                        Console.WriteLine (string.Format("I'm a {0} with area of {1} derived from {2}", square.Draw(), square.Area(), square.DrawBase()) );
                        break;
                    default:
                        break;
                }
            }
        }
    }

    abstract class DrawingObject
    {
    // Area() function must be over ridden in derived classes to provide specific functionality
        public abstract double Area();
    // DrawBase will be common to all derived classes
        public  string DrawBase()
        {
           return "DrawingObject";
        }
    }

    class Square : DrawingObject
    {
        public int Width { get; set; }
        public int Length { get; set; }

        public Square(int width, int length)
        {
            Width = width;
            Length = length;
        }

        public  string Draw()
        {
            return "Square";
        }

        public override double Area ()
        {
            return (Width * Length);
        }
    }

    class Circle : DrawingObject
    {
        public int Radius { get; set; }

        public Circle(int radius)
        {
            this.Radius = radius;
        }

        public  string Draw()
        {
            return "Circle";
        }

      public override double Area ()
      {
         return (Math.Pow(Radius,2)*Math.PI);
      }
    }
}