#include <iostream>


using namespace std;

double pi = 3.1415;

void printa(double r);
int main()
{

double r, p;
cout<< "Enter the radius: ";
cin>> r;
cout<< "Enter the value of pi: ";
cin>> p;
cout<< "The area calculated in main: "<< (p*r*r)<<endl;

cout<< "The area calculatd in function: ";
 printa( r);

    return 0;
}

void printa(double r){
  cout<< pi*r*r;

}