#include<stdio.h>
#define PI 3.14
#define kare(x) (x*x)
#define dairealani(r) PI*kare(r)
main()
{
float yaricap,alan;
printf("Dairenin Yaricapini Girin:");scanf("%f",&yaricap);
alan=dairealani(yaricap);
printf("Islem Sonucu=%f",alan);
}
