Помогите плиз с задачкой.

 #include  

#include  

#include  

#include  

#include  

 

using namespace std; 

 

class Point { 

public: 

    Point() 

        : x(0), y(0) {} 

    Point(const double x, const double y) 

        : x(x), y(y) {} 

    double length(const Point& p)const { 

        return sqrt(pow(p.x - x, 2) + pow(p.y - y, 2)); 

    } 

private: 

    double x; 

    double y; 

}; 

 

class Triangle { 

public: 

    Triangle() = default; 

    Triangle(const Point& pa, const Point& pb, const Point& pc) 

        : pa(pa), pb(pb), pc(pc) {} 

    double area()const { 

        auto [a, b, c] = sides(); 

        auto p = (a + b + c) / 2.0; 

        return sqrt(p * (p - a) * (p - b) * (p - c)); 

    } 

private: 

    Point pa; 

    Point pb; 

    Point pc; 

    tuple sides()const { 

        return { pa.length(pb), pb.length(pc), pc.length(pa) }; 

    } 

}; 

 

class Command { 

public: 

    Point position()const { 

        istringstream iss(line); 

        string g_code; 

        iss >> g_code; 

        string pos_x; 

        iss >> pos_x; 

        auto x = stod(string{ pos_x.begin() + 1, pos_x.end() }); 

        string pos_y; 

        iss >> pos_y; 

        auto y = stod(string{ pos_y.begin() + 1, pos_y.end() }); 

        return { x, y }; 

    } 

private: 

    string line; 

    friend istream& operator>>(istream& inp, Command& command) { 

        getline(inp, command.line); 

        return inp; 

    } 

}; 

 

int main() { 

    Command a, b, c; 

    cin >> a >> b >> c; 

    Triangle triangle{ a.position(), b.position(), c.position() }; 

    const auto area = triangle.area(); 

    cout.setf(ios::fixed); 

    cout.precision(3); 

    cout