C :

#include <stdio.h>

#define PI 3.1415926535

int main(void) {
	double r;
	scanf("%lf", &r);
	printf("%.2f\n%.2f\n", PI*r*r, 2*PI*r);
	return 0; 
}

C++ :

#include<cstdio>
using namespace std;
int main()
{
	double r,s,l;
	scanf("%lf",&r);
	s=r*r*3.1415926535;
	l=2*r*3.1415926535;
	printf("%.2lf\n",s);
	printf("%.2lf\n",l);
	return 0;
}

Pascal :

Program ygjsb;
const pi=3.1415926535;
  Var
   r,c,s:real;
  begin
   read(r);
   c:=2*pi*r;
   s:=pi*r*r;
   writeln(s:0:2);
   write(c:0:2);
  end.