A C Program to find area of sphere.

#include<stdio.h>
#include<conio.h>
#include<math.h>
#define pi 3.14
void main()
{
int r,a;
clrscr();
printf("Enter radius:");
scanf("%d",&r);
a=(4/3)*pi*r*r*r;
printf("Area of sphere:%d",a);
getch();
}