01  #include<stdio.h>
02  
03  int main()
04  {
05  int radius;
06  float cir;
07  
08  printf("Enter Radius of the Circle : ");
09  scanf("%d",&radius);
10  
11  cir=2*3.14*radius;
12  
13  printf("Circumference of the Circle : %.2f",cir);
14  return 0;
15  }

 OUTPUT :
 
 Enter Radius of the Circle : 5
 Circumference of the Circle : 31.40