11. Geometry Calculator

using System;

namespace Geometry_Calculator
{
    class Program
    {
        static void Main(string[] args)
        {
            string type = Console.ReadLine().ToLower().Trim();
            Cases(type);
        }

        private static void Cases(string type)
        {
            switch (type)
            {
                case "triangle":
                    Triangle();
                    break;
                case "square":
                    Square();
                    break;
                case "rectangle":
                    Rectangle();
                    break;
                case "circle":
                    Circle();
                    break;
                default:
                    break;
            }
        }

        static void Triangle()
        {
            double baseValue = double.Parse(Console.ReadLine());
            double heightValue = double.Parse(Console.ReadLine());
            double areaOfTriangle = ((baseValue * heightValue) / 2);
            Console.WriteLine("{0:f2}",areaOfTriangle);
        }

        static void Square()
        {
            double baseValue = double.Parse(Console.ReadLine());
            double areaOfSquare = Math.Pow(baseValue, 2);
            Console.WriteLine("{0:f2}", areaOfSquare);
        }

        static void Rectangle()
        {
            double length = double.Parse(Console.ReadLine());
            double width =double.Parse(Console.ReadLine());
            double areaOfRectangle = length * width;
            Console.WriteLine("{0:f2}", areaOfRectangle);
        }

        static void Circle()
        {
            double radius =double.Parse(Console.ReadLine());
            double areaOfCircle = Math.PI * Math.Pow(radius, 2);
            Console.WriteLine("{0:f2}", areaOfCircle);
        }
    }
}