using System;

public class circle

{

static float pi=3.14f;

    static circle ()

    {

    Console.WriteLine("Static Constructor");

    }

     int radius;

public circle(int radius)

{

    this.radius=radius;

    Console.WriteLine("Instance Constructor:");

}

​

public float calculatearea()

    {

        return circle.pi*this.radius*this.radius;

    }

​

​

public static void Main()

    {   

        circle c1=new circle(5);

        float Area=c1.calculatearea();

        Console.WriteLine("Area of circele is {0} ",Area);

    circle c2=new circle(10);

    float Area2=c2.calculatearea();

    Console.WriteLine("Area of circele is {0} ",Area2);

        }

    }

​