using System;

public class Program

{

    public static void Main()

    {

        Square squ1 = new Square(5.5);

        Console.WriteLine(squ1.Area);

    }

}

​

​

//public class Shape

public class Shape

{

    public double Area { get; set; }

    public Shape()

    {

        Area = 0;   

    }

}

​

//public class Square

public class Square : Shape

{

    public double Side { get; set; }

    public Square(double side)

    {

        Side = side;

        Area = side * side;

    }

}

​

public class Circle : Shape

{

    public double Radius { get; set; }

    public Circle(double radius)

    {

        Radius = radius;

        Area = Math.PI * Math.Pow(radius, 2);

    }

    public void DisplayCircleInfo()

    {

        Console.WriteLine("Circle Radius: {Radius}, Area: {Area}");

    }

    public double CalculateCircumference()

    {

        return 2 * Math.PI *  Radius;

    }

}

​

public class Programm   

{

    public static void Main(string[] args)

    {

        Circle circle = new Circle(5);

        circle.DisplayCircleInfo();

        Console.WriteLine("Circumference: {circle.CalculateCircumference()} ");

    }

}