C :

#include <stdio.h>
int main(){
	int n;
	scanf("%d",&n);
	
	printf("%.2f\n%.2f",3.1415926 * n * n,3.1415926*2*n);


	return 0;
}

C++ :

#include <iostream>
#include <iomanip>

using namespace std;

int main(){
	int r;
	cin>>r;
	double pi = 3.1415926,s,c;
	s = pi * r * r;
	c = pi * 2 * r;
	cout<<fixed<<setprecision(2)<<s<<endl;
	cout<<fixed<<setprecision(2)<<c<<endl;
	return 0;
}

Pascal :

    var n,m:longint; 
    begin
            readln(n);
            writeln(n*n*3.1415926:0:2);
            writeln(n*2*3.1415926:0:2);
    end.

Java :

import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();
		float pi=(float)3.1415926;
		float x =(float)(pi*n*n);
		float y =(float)(pi*2*n);
		System.out.printf("%.2f",x);
		System.out.println("");
		System.out.printf("%.2f",y);
	}
}

Python :

r = int(input())
s = 3.1415926 * r * r;
c = 3.1415926 * r * 2;
print('%.2f' % s)
print('%.2f' % c)