[java] 소수점 자르기

import java.io.IOException;
import java.util.*;

public class Main {

public static double w=0;

   public static void main(String[] args) throws IOException {

      Scanner sc = new Scanner(System.in);

          double r = sc.nextInt() ;

      double ret;
          ret= r*r*2;
      
          r = pfm(r);


        //  System.out.println(Math.round(r*1000000)/1000000.0);
        //  System.out.println(Math.round(ret*100)/100.0);
          System.out.println(String.format("%.6f",r));
          System.out.println(String.format("%.6f",ret));

   } // end of Main
   
   public static double pfm(double r){
   
      w = r*r*Math.PI;

          return w;

   }
                 
} // end of class Main