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;
using System.Text;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            double r = double.Parse(s);
            double pi = 3.14159265358979323846;

            double area = r * r * pi;
            double ensyu = r * pi * 2;
            string area2 = string.Format("{0:f6}", area);
            string ensyu2 = string.Format("{0:f6}", ensyu);
            Console.WriteLine(area2 + " " + ensyu2);

        }
    }
}