using System;

public class Program

{

    public static void Main(String[] args)

    {

        Square s = new Square (2.4);

        Console.WriteLine ("Area of Circle = {0}, c.GetArea());

        Circle c = new Circle (3.0);

        Console.WriteLine ("Area of Circle = {0}, c.GetArea());

                           }

                           }

abstract class Shape

{

    public abstract double GetArea();

}

​

class Square: Shape

{

private double side;

public square (double s)

{

side = s;

}

public override double GetArea()

{

}

}

​

class Circle: Shape

{

public double radius;

public Circle (double r)

{

radius = r;

}

public override double GetArea()

{

}

}

​

​

​

​