C语言的题目，求解答

Question

Answer 1

#include <stdio.h>
#include <math.h>
int main()
{
    double a,b,c,s,area;
    scanf("%lf %lf %lf",&a,&b,&c);
    if( a+b > c && b+c > a && a+c>b)
    {
        s = (a+b+c)/2;
        area = sqrt(s*(s-a)*(s-b)*(s-c));
        printf("%.2lf",area);
    }else
        printf("不能组成三角形");
    
    return 0;
}