哪位看一下这道简单题啊😬

Question

u等会等会黑道皇后合适的话还是等会等会好的好的不好的话就（凑字数）

Answer 1

#include <stdio.h>
#include <math.h>
int main()
{
    double area = 0;
    double s;
    double a,b,c;
    double x1,y1,x2,y2,x3,y3;
    scanf("%lf%lf%lf%lf%lf%lf", &x1,&y1,&x2,&y2,&x3,&y3);
    a = sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2));
    b = sqrt((x1-x3)*(x1-x3) + (y1-y3)*(y1-y3));
    c = sqrt((x3-x2)*(x3-x2) + (y3-y2)*(y3-y2));
    s = (a+b+c) / 2;
    area = sqrt(s * (s - a) * (s - b) * (s - c));
    printf("%.2lf",area);
    return 0;
}