C#_CircleParameterAndArea.cs

using System;


    class CircleParameterAndArea
    {
        static void Main()
        {
            Console.WriteLine("Please enter radius of your circle:");
            double r = double.Parse(Console.ReadLine());
            double perimeter = 2 * Math.PI * r;
            double area = Math.PI * Math.Pow(r, 2);
            Console.WriteLine("The perimeter of your circle is {0:0.00} and his area is {1:0.00}", perimeter, area);

        }
    }