extDefPi

#include <stdio.h>
void g_PI();
const double PI = 3.14159;

double cVerPi(double r){

    double sum = 0;
    sum = PI*r*r;
    printf ("\n%f", sum);
    return sum;
}

double secFunc(double a, double b){
    double sumForSecFunc = 0;
    sumForSecFunc = PI * a * b;
    printf("\n%f", sumForSecFunc);
    return sumForSecFunc;
}

int main() {
    cVerPi(1);
    cVerPi(1.5);
    cVerPi(13);

    secFunc(1, 1);
    secFunc(2, 2);
    secFunc(3, 3);

    return 0;

}