WAP to Use of macro expansion2

/*WAP to Use of macro expansion*/

#include<stdio.h>
#include<conio.h>
#define PI  3.1415
main( )
{
 float  r = 6.25 ;
 float  area ;

 area = PI * r * r ;
 printf ( "\nArea of circle = %f", area ) ;
 getch();
}