C Program to show Macro Substitution with Arguments

#include <stdio.h>

#include <conio.h>

 

#define circumference(r) (2*3.141*(r))

 

int main(){

    int radius;

    float c;

    printf("Enter the radius of circle\n");

    scanf("%d", &radius);

     

    c = circumference(radius);

     

    printf("Circumference of Circle = %f", c);

     

    getch();

    return 0;

}