c program for radius of circle define pi

Question

C Program for RADIUS OF CIRCLE

 

#define PI 3.14159

main()

{

          float r,a;

          clrscr();

          printf("ENTER THE RADIUS OF A CIRCLE: ");

          scanf("%f",&r);

          a=PI*r*r;

          printf("\NTHE AREA OF A CIRCLE IS %f",a);

          getch();

}

 

OUTPUT :

 ENTER THE RADIUS OF A CIRCLE: 5

THE AREA OF A CIRCLE IS 78.539743