C :

#include<stdio.h>
#define PI 3.1415926
void main()
{
	double r;
	scanf("%lf",&r);
	printf("%.2f\n",PI*r*r);
	printf("%.2f\n",2*PI*r);
}

C++ :

#include<iostream>
using namespace std;
const float pi(3.1415926);
int main()
{
    float r,s,c;
    cin>>r;
    s=pi*r*r;  
    c=2*pi*r;
    cout.precision(2);
    cout.setf(ios::fixed);
    cout<<s<<endl;
    cout<<c<<endl;
    //system("pause");
    return 0;
}

Pascal :

program aa;
var a,b,c,d,e:real;
begin
 read(a);
 b:=3.1415926;
 c:=a*a*b;
 d:=a*2*b;
 write(c:0:2);
 writeln;
 write(d:0:2);
end.