static void Main(string[] args)
{
Circle circle1 = new Circle(5);
Circle circle2 = new Circle(10);
Console.WriteLine("Display info of circle1 is {0}", circle1.displayCircleInfo());
Console.WriteLine("Display info of circle2 is {0}", circle2.displayCircleInfo());
circle2.Radius = -5;
Console.WriteLine("Display info of Changed circle2 is {0}", circle2.displayCircleInfo());
Console.ReadLine();
}
