Question

По координатам трёх вершин некооторого треугольника найдите его площадь и периметр

Answer 1

#include <iostream>
#include <math.h>

using namespace std;

class Vertice {
public:
    double x, y;
    friend istream &operator>>(istream &is, Vertice &v) {
        is >> v.x >> v.y ;
    }
    double distance(Vertice &w);
};

double Vertice::distance(Vertice &w) {
    return sqrt( pow(this->x-w.x,2) + pow(this->y-w.y,2));
}

class Triangle {
public:
    Vertice a, b, c;
    Triangle(Vertice v, Vertice w, Vertice u);
    double Square();
    double Perimetr();
};

Triangle::Triangle(Vertice v, Vertice w, Vertice u) {
    this->a = v, this->b = w, this->c = u;
}

double Triangle::Perimetr() {
    return this->a.distance(this->b) + this->a.distance(this->c) + this->b.distance(this->c);
}

double Triangle::Square() {
    double a = this->a.distance(this->b), b = this->b.distance(this->c), c = this->a.distance(this->c),
        p = (a+b+c)/2;
    return sqrt(p*(p-a)*(p-b)*(p-c));
}

int main() {
    Vertice a, b , c;
    cin >> a >> b >> c;
    Triangle t(a,b,c);
    cout << t.Perimetr() << endl << t.Square() << endl;
}

//язык c++, ООП