area of circle c cpus plus tutorial in hindi

area of circle program

#include<stdio.h>
#include<conio.h>
void main()
{
    int r;
    float area,pi=3.14;
    clrscr();
    printf("Enter the radius=");
    scanf("%d",&r);
    area=pi*r*r;
    printf("Area of circle=%4f",area);
    getch();
}