#include<stdio.h>
main()
{
 double area(double r),circumference(double r);
 printf("area=%f",area(2.0));
 printf("\tcircumference=%f\n".circumference(2.0));
}
double area(double r)
{
 return(3.14152654*r*r);
}
double circumference(double r)
{
 return(2.0*3.1415926*r);
}