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


using namespace std;
class Punkt {
public:
    float x;
    float y;
    void display()
    {
        cout<<"("<<x<<", "<<y<<")";
    }
    Punkt(float positionX, float positionY) {
    x=positionX;
    y=positionY;}

    Punkt(){
    x=0;
    y=0;
}

};
class Trojkat{
public:
    Punkt A, B, C;
     float liczPole()
     {
        float AB = sqrt((A.x - B.x)*(A.x - B.x)+(A.y - B.y)*(A.y - B.y));
        float d, e, f;
        d=(B.y-A.y)/(B.x-A.x);
        e=A.y-d*A.x;
        //C.y=(-1/d)*C.x+f
        f=C.y-(-1/d)*C.x;
        Punkt P;
       //y=d*x+e
        //y=(-1/d)*x+f
        //d*x+e=(-1/d)*x+f
        //d*x+(1/d)*x=f-e
        P.x=(f-e)/(d+(1/d));
        P.y=(-1/d)*P.x+f;
        float PC = sqrt((P.x - C.x)*(P.x - C.x)+(P.y - C.y)*(P.y - C.y));
        return (AB*PC)/2;
     }
     float liczObwod()
     {
         float AB = sqrt((A.x - B.x)*(A.x - B.x)+(A.y - B.y)*(A.y - B.y));
         float BC = sqrt((C.x - B.x)*(C.x - B.x)+(C.y - B.y)*(C.y - B.y));
         float CA = sqrt((C.x - A.x)*(C.x - A.x)+(C.y - A.y)*(C.y - A.y));
         return AB+BC+CA;
     }
};

int main()
{


    return 0;
}