triangle area finding

 #include <stdio.h>

#include <math.h>

int main()

{

float a,b,c,sp,area,squareroot,num;

printf("\n Enter sides of triangle\n");

scanf("%f %f %f",&a,&b,&c);

sp=(a+b+c)/2;

num =(sp*(sp-a)*(sp-b)*(sp-c));

area = sqrt(num);

printf("Area of triangle %f\n",area);

return 0;

}