static void Main(string[] args) { Console.WriteLine("1-Rectangle\n2-Triangle\n3-Circle"); Console.WriteLine("Enter Choice: "); int choice = Convert.ToInt16(Console.ReadLine()); if (choice == 1) { Console.WriteLine("RECTANGLE CLASS"); Rectangle rt = new Rectangle(); Console.WriteLine("Enter Length: "); rt.length = Convert.ToDouble(Console.ReadLine()); Console.WriteLine("Enter Breadth: "); rt.breadth = Convert.ToDouble(Console.ReadLine()); double rtArea = rt.calcArea(); Console.WriteLine("Area of Rectangle is: " + rtArea); } else if (choice == 2) { Console.WriteLine("TRIANGLE CLASS"); Triangle t = new Triangle(); Console.WriteLine("Enter Length1 : "); t.l1 = Convert.ToDouble(Console.ReadLine()); Console.WriteLine("Enter Length2 : "); t.l2 = Convert.ToDouble(Console.ReadLine()); Console.WriteLine("Enter Length3 : "); t.l3 = Convert.ToDouble(Console.ReadLine()); double tArea = t.getArea(); Console.WriteLine("Area of Triangle is : " + tArea); } else if (choice == 3) { Console.WriteLine("CIRCLE CLASS"); Circle circle = new Circle(); Console.WriteLine("Enter Radius: "); circle.radius = Convert.ToDouble(Console.ReadLine()); double AreaCircle = circle.getArea(); Console.WriteLine("Area of Circle is : " + AreaCircle); } else { Console.WriteLine("You Entered Wrong Choice!!"); } }