C program to Find volume of spehre

SOURCE CODE:
#include<stdio.h>
#include<conio.h>
void main()
{
 float pi=3.14,v,r;
 clrscr();
 printf("enter radius of spehre :");
 scanf("%f",&r);
 v=(float)4/3*pi*r*r*r;
 printf("volume of spehre is %f",v);
 getch();
}