24.05.17

#include <iostream>
#include <cmath>
using std::cin;
using std::cout;
using std::endl;
struct Point
{
    double x;
    double y;
    double z;
};
double distance(Point A, Point B)
{
    return sqrt(pow((A.x - B.x), 2) + pow((A.y - B.y), 2) + pow((A.z - B.z), 2));
}
double Perimetre(Point A, Point B, Point C)
{
    return distance(A, B) + distance(B, C) + distance(A, C);
}
double Square(Point A, Point B, Point C)
{
    return sqrt((Perimetre(A, B, C) / 2)*((Perimetre(A, B, C) / 2) - distance(A, B))*((Perimetre(A, B, C) / 2) - distance(B, C))*((Perimetre(A, B, C) / 2) - distance(A, C)));
}
int main()
{
    setlocale(LC_ALL, "RUSSIAN");
    Point A{ 1, 5, 9 },
        B{ 2, 7, 4 },
        C{ 3, 1, 0 };
    cout << " " << endl;
    cout << "Периметр треугольника ABC: " << Perimetre(A, B, C) << endl;
    cout << "Площадь треугольника ABC: " << Square(A, B, C) << endl;
    return 0;
}


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Ф И Н А Л О Ч К А

#include <iostream>
#include <cmath>
using std::cin;
using std::cout;
using std::endl;
struct Point
{
    double x;
    double y;
    double z;
};
double distance(Point A, Point B)
{
    return sqrt(pow((A.x - B.x), 2) + pow((A.y - B.y), 2) + pow((A.z - B.z), 2));
}
double Perimetre(Point A, Point B, Point C)
{
    return distance(A, B) + distance(B, C) + distance(A, C);
}
double Square(Point A, Point B, Point C)
{
    return sqrt((Perimetre(A, B, C) / 2)*((Perimetre(A, B, C) / 2) - distance(A, B))*((Perimetre(A, B, C) / 2) - distance(B, C))*((Perimetre(A, B, C) / 2) - distance(A, C)));
}
void Input(Point&P)
{
    cout << "x:";
    cin >> P.x;
    cout << "y:";
    cin >> P.y;
    cout << "z:";
    cin >> P.z;
}
void Display(Point P)
{
    cout << "{" << P.x << ", " << P.y << ", " << P.z << "}";
}
int main()
{
    setlocale(LC_ALL, "RUSSIAN");
    Point A, B, C;
    cout << "Введите точки:" << endl;
    Input(A);
    cout << " " << endl;
    Input(B);
    cout << " " << endl;
    Input(C);
    cout << " " << endl;
    cout << "Вы ввели точки:" << endl;
    Display(A);
    cout << " " << endl;
    Display(B);
    cout << " " << endl;
    Display(C);
    cout << " " << endl;
    cout << "Периметр треугольника ABC: " << Perimetre(A, B, C) << endl;
    cout << "Площадь треугольника ABC: " << Square(A, B, C) << endl;
    return 0;
}