#include<stdio.h> 
  #include<conio.h> 
  #define PI 3.14 
  main() 
  { 
   
  float area,r; 
  printf("Yari capi giriniz:"); 
  scanf("%f",&r); 
  area=PI*r*r; 
  printf("area=%.2f",area); 
  getch(); 
  }

#include<stdio.h> 
  #include<conio.h> 
  #define PI 3.14 
  main() 
  { 
  float area,r; 
  printf("\nYari capi giriniz:"); 
  scanf("%f",&r); 
  while(r!=0) 
  { 
  area=PI*r*r; 
  printf("\narea=%.2f",area); 
  getch(); 
  } 
   
  }