Problem:
Circle

Write a program which calculates the area and circumference of a circle for given radius r.

Input

A real number r is given.

Output

Print the area and circumference of the circle in a line. Put a single space between them. The output should not contain an absolute error greater than 10-5.

Constraints

0 < r < 10000

Sample Input 1

2

Sample Output 1

12.566371 12.566371

Sample Input 2

3

Sample Output 2

28.274334 18.849556

Solution in C# (judge verdict: Accepted)

using System;
using System.Collections.Generic;

//namespace _4_B

class Program
{
    static void Main(string[] args)
    {
        //??\??????????????°???????????????
        double r = double.Parse(Console.ReadLine());

        //??¢???????¨??????????
        double equivalent = 3.141592653589 * Math.Pow(r, 2);

        //string??????????????????????????????????????¨?????????
        string e = equivalent.ToString("F6");

        //??¨?????????????¨??????????
        double around = 2 * 3.141592653589 * r;

        //string??????????????????????????????????????¨?????????
        string a = around.ToString("F6");

        //?????????????????????
        Console.WriteLine(e + " " + a);

    }
}