How To Calculate Area of A Circle in C

#include <stdio.h>

int main()

{

   int r;

   float pi=3.1416,area=0.0;

   printf("Please Enter The Radius of The Circle: ");

   scanf("%d",&r);

   area=pi*r*r;

   printf("
Area of The Circle is: %f
",area);

    return 0;

}