Geometry Calculator

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace GeometryCalculator
{
    class Program
    {
        static void Main(string[] args)
        {
            string figure = Console.ReadLine();
            if (figure == "square" || figure == "circle")
            {
                GetArea(figure, double.Parse(Console.ReadLine()));
            }
            else
            {
                GetArea(figure, double.Parse(Console.ReadLine()), double.Parse(Console.ReadLine()));
            }
        }

        public static void GetArea(string figure, double num1, double num2 = 42) // 42 = The answer to life the universe and everything
        {

            switch (figure.ToLower())
            {
                case "triangle":
                    Console.WriteLine("{0:0.00}",  num1 * num2 / 2);
                    break;
                case "square":
                    Console.WriteLine("{0:0.00}", num1 * num1);
                    break;
                case "rectangle":
                    Console.WriteLine("{0:0.00}", num1 * num2);
                    break;
                case "circle":
                    Console.WriteLine("{0:0.00}", Math.PI * (num1 * num1));
                    break;
                default:
                    break;
            }
        }

    }
}