5-1

#include<stdio.h>
int main(void)
{
    double height,radius,volume;
    double cylinder(double r,double h);

    printf("Enter radius and height:");
    scanf("%lf%lf",&radius,&height);
    volume=cylinder(radius,height);
    printf("Volume=%.3f\n",volume);

    return 0;
}

double cylinder(double r,double h)
{
    double result;
    
    result=3.1415926*r*r*h;

    return result;
}