#include <iostream>
#include <cmath>
#include "point.h"
using namespace std;

point:: point();
point::point(double x, double y);
double point::x() const;
double point::y() const;
double point::distance(point & p) const;
triangle::triangle();
triangle::triangle(point a, point b, point c);
point triangle::p1();
point triangle::p2();
point triangle::p3();
double triangle::area();
point triangle::center();
void triangle::shift(point v);


point::point()
:my_x(0), my_y(0)
{
}

point::point(double x, double y)
:my_x(x), my_y(y)
{
}

double point::x() const
{
    return my_x;
}

double point::y() const
{
    return my_y;
}

double point::distance(point & p) const
{
    return sqrt(pow(my_x-p.my_x,2)+pow(my_y-p.my_y,2));
}

bool point_eq(point & a, point & b)
{
    return ((a.my_x == b.my_x) && (a.my_y == b.my_y));
}


triangle::triangle()
{
    my_p1 = point(0,0); 
    my_p2 = point(0,0); 
    my_p3 = point(0,0);
}

triangle::triangle(point a, point b, point c)
{
    my_p1 = a;  
    my_p2 = b;  
    my_p3 = c;
}

point triangle::p1()
{
    return my_p1;
}

point triangle::p2()
{
    return my_p2;
}

point triangle::p3()
{
    return my_p3;
}

double triangle::area()
{
    double a,b,c,s,Area;
    a = my_p1.distance(my_p2);
    b = my_p2.distance(my_p3);
    c = my_p3.distance(my_p1);
    s = (a+b+c)/2;
    Area = sqrt(s*(s-a)*(s-b)*(s-c));
    return Area;
}

point triangle::center()
{
    double x,y;
    x = (my_p1.my_x+my_p2.my_x+my_p3.my_x)/3.0;
    y = (my_p1.my_y+my_p2.my_y+my_p3.my_y)/3.0;
    return point(x,y);
}

void triangle::shift(point v)
{
    my_p1.my_x += v.x();
    my_p1.my_y += v.y();
    my_p2.my_x += v.x();
    my_p2.my_y += v.y();
    my_p3.my_x += v.x();
    my_p3.my_y += v.y();
}