Calculate the Area of a Triangle(three sides,heron's formul)

#include<stdio.h>
#include<math.h>
#include<conio.h>
//Calculate area of the triangle when three sides are given
int main()
{
    int a,b,c;
    double s,area;
    printf("Enter three values: \n");
    scanf("%d %d %d",&a,&b,&c);
    s=(a+b+c)/2;
    area = sqrt(s*(s-a)*(s-b)*(s-c));//its Heron's formula for the area of a triangle
    printf("area of triangle : %.2lf",area);
    getch();
    return 0;

}