using System;

public class Program

{

    public static void Main()

    {

        // create an instance of the Rectangle class called MyRectangle & define it's properties

            Rectangle MyRectangle = new Rectangle();

            MyRectangle.Height = 4;

            MyRectangle.Width = 2;

            // Use the overridden Area method to display the area of MyRectangle

            MyRectangle.Area();

​

            // create an instance of the Triangle class called MyTriangle & define it's properties

            Triangle MyTriangle = new Triangle();

            MyTriangle.Height = 4;

            MyTriangle.Width = 2;

            // Use the overridden Area method to display the area of MyTriangle

            MyTriangle.Area();

​

            // create an instance of the Circle class called MyCircle & define it's properties

            Circle MyCircle = new Circle();

            MyCircle.Radius = 4;

            // Use the overridden Area method to display the area of MyTriangle

            MyCircle.Area();

    }

}

​

class Shape

    {

        // Define some generic properties for this class

        private int height;

        private int width;

        private int

​

        //  This is the CONSTRUCTOR to allow you to create an instance of this class

        public Shape() { }

​

        // Define the accessor functions for this class

        public int Height

        {

            get { return this.height; }

            set { this.height = value; }

        }

        public int Width

        {

            get { return this.width; }

            set { this.width = value; }

        }

​

        // This virtual method defines a calculation for the sare of the generic shape

        public virtual void Area()

        {

            Console.WriteLine("The area of the shape is yet to be defined");

        }

    }

​

    class Rectangle : Shape

    {

        // No need to define any further properties, as they are inherited from the class Shape

​

        // Define the CONSTRUCTOR

        public Rectangle() { }

​

        //  No need to define further accessors, as they are inherited from the class Shape

​

        // Override the inherited Area method

        public override void Area()

        {

            Console.WriteLine("The area of the MyRectangle is {0}", Width * Height);

        }

    }

​

    class Triangle : Shape

    {

        // No need to define any further properties, as they are inherited from the class Shape

​

        // Define the CONSTRUCTOR

        public Triangle() { }

​

        //  No need to define further accessors, as they are inherited from the class Shape

​

        // Override the inherited Area method

        public override void Area()

        {

            Console.WriteLine("The area of the MyTriangle is {0}", 0.5 * Width * Height);

        }

    }

​

    class Circle : Shape

    {

        // Define a new property for the class Circle called radius

        private int radius;

​

        // Define the CONSTRUCTOR

        public Circle() { }

​

        //  Define the accessors

        public int Radius

        {

            get { return this.radius; }

            set { this.radius = value; }

        }

​

        // Override the inherited Area method

        public override void Area()

        {

            Console.WriteLine("The area of the MyCircle is {0:0.00}", Math.PI * radius * radius);

        }

    }