Решение задачи Треугольник и точка с Acmp

#include <iostream>
#include <string>
#include <vector>
#include <cmath>
using namespace std;
 
long double Storona(long double x1,long double y1,
               long double x2,long double y2,
               long double x3,long double y3)
{
    long double  a, b, c, p, s;
    a = sqrt(pow((x1 - x2),2) + pow((y1 - y2),2));
    b = sqrt(pow((x2 - x3),2) + pow((y2 - y3),2));
    c = sqrt(pow((x1 - x3),2) + pow((y1 - y3),2));
    p = (a + b + c) / 2.;
    s = sqrt(p * (p - a) * (p - b) * (p - c));
    return s;
     
}
int main()
{
    long double x1,y1,x2,y2,x3,y3,xz,yz;
    long double s,s1,s2,s3;
    cin >> x1 >> y1 >> x2 >> y2 >> x3 >> y3 >> xz >> yz;
    s = Storona(x1,y1,x2,y2,x3,y3);
    s1 = Storona(x1,y1,x2,y2,xz,yz);
    s2 = Storona(x2,y2,xz,yz,x3,y3);
    s3 = Storona(x1,y1,x3,y3,xz,yz);
    if(abs(s1 + s2 + s3 - s) < 0.1e-7)
        cout << "In";
    else
        cout << "Out";
    return 0;
}