using System;

public class Program

{

    public static void Main(string[] args)

    {

        Circle c1 = new Circle();

        Console.WriteLine("The cirlce has radius of " + c1.getRadius() + " and area of " + c1.getArea());

        Circle c2 = new Circle(2.0);

        Console.WriteLine("The cirlce has radius of " + c2.getRadius() + " and area of " + c2.getArea());

        Circle c3 = new Circle(3.0);

        Console.WriteLine("The cirlce has radius of " + c3.getRadius() + " and area of " + c3.getArea() + " and its colour is " + c3.getColour());

        Console.WriteLine("colour is " + c3.getColour());

        Circle c4 = new Circle();

        c4.setRadius(5.5);

        Console.WriteLine("Radius: " + c4.getRadius());

        c4.setColour("green");

        Console.WriteLine("Colour: " + c4.getColour());

        Circle c5 = new Circle(5.5);

        Console.WriteLine(c5.toString());

    }

}

​

​

class Circle {

    private double radius;

    private string colour;

    public Circle() {

        radius = 1.0;

        colour = "red";

    }

    public Circle(double radius) {

        this.radius = radius;

        colour = "red";

    }

    public double getRadius() {

        return radius;

    }

    public double getArea() {

        return radius*radius*Math.PI;

    }

    public Circle(double radius, string c) {

        this.radius = radius;

        colour = c;

    }

    public string getColour() {

        colour = "green";

        return colour;

    }

    public void setRadius(double radius) {

        this.radius = radius;

    }

    public void setColour(string newColour) {

        colour = newColour;

    }

    public string toString() {

        return "Circle[radius=" + radius + " colour=" + colour + "]";

    }

}