Лица на фигури

using System;

namespace tESt
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Enter one of the figure");
            Console.WriteLine();
            Console.WriteLine("square, rectangle, circle or triangle");
            string type = Console.ReadLine();


            if (type == "square")
            {
                double sideA = double.Parse(Console.ReadLine());
                Console.WriteLine(sideA * sideA);
            }
            else if (type == "rectangle")
            {
                double sideA = double.Parse(Console.ReadLine());
                double sideB = double.Parse(Console.ReadLine());
                Console.WriteLine(sideA * sideB);
            }
            else if (type == "circle")
            {
                double sideR = double.Parse(Console.ReadLine());
                Console.WriteLine(sideR * sideR * Math.PI);
            }
            else if (type == "triangle")
            {
                double sideA = double.Parse(Console.ReadLine());
                double hight = double.Parse(Console.ReadLine());
                Console.WriteLine(sideA * hight / 2.0);
            }
            else
            {
                Console.WriteLine("ERROR!");
            }

        }


    }

}