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 JAVA (judge verdict: Accepted)

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO ?????????????????????????????????????????????
		Scanner sc = new Scanner(System.in);
		String line = sc.nextLine();
		double r = Double.parseDouble(line);
		double pi = Math.PI;
		double menseki = r * r * pi;
		double enshuu = 2 * r * pi;
		System.out.printf("%.8f", menseki);
		System.out.print(" ");
		System.out.printf("%.8f", enshuu);
	}

}