Маштаб треугольника

//
// Created by User on 31.10.2016.
//
 
#ifndef PROST_POINT_H
#define PROST_POINT_H
 
 
class Point {
public:
    Point(int x, int y);
 
    void draw();
    void expand(int a);
 
 
    void move(int dx, int dy);
 
    int x() const;
 
    int y() const;
 
 
private:
    int _x;
    int _y;
 
};
 
 
#endif //UNTITLED23_POINT_H

#include "Point.h"
#include <iostream>
 
using namespace std;
 
Point::Point(int x, int y) {
 
    _x = x;
    _y = y;
 
}
 
void Point::draw() {
    cout << "x=" << _x  << " ,y=" << _y << endl;
 
}
 
void Point::move(int dx, int dy) {
 
    _x *= dx;
    _y *= dy;
 
}
void Point::expand(int a){
   _x*=a;
    _y*a;
 
}
 
int Point::x() const {
    return _x;
}
 
int Point::y() const {
    return _y;
}

#ifndef PROST_LINE_H
#define PROST_LINE_H
 
 
#include "Point.h"
 
class Line {
public:
    Line(Point *p1, Point *p2);
 
    void draw();
    void move(int dx, int dy);
    void expand(int a);
    double lenght();
    void printLenght();
 
    Point *p1(){return _p1;}
    Point *p2(){return _p2;}
 
 
 
private:
    Point *_p1;
    Point *_p2;
 
};
 
 
#endif //UNTITLED23_LINE_H

//
// Created by User on 31.10.2016.
//
 
#include "Line.h"
 
#include <iostream>
#include <math.h>
 
using namespace std;
 
Line::Line(Point *p1, Point *p2) {
 
    _p1 = p1;
    _p2 = p2;
 
}
void Line::expand(int a){
    _p1->expand(a);
    _p2->expand(a);
 
}
void Line::draw() {
 
    _p1->draw();
    _p2->draw();
}
 
void Line::move(int dx, int dy) {
    _p1->move(dx, dy);
 
    _p2->move(dx, dy);
 
}
 
double Line::lenght() {
    double lenght;
    int x1 = _p1->x();
    int x2 = _p2->x();
    int y1 = _p1->y();
    int y2 = _p2->y();
   lenght = sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
 
    return lenght;
}
 
void Line::printLenght(){
    cout << "Lenght line= " << lenght() << endl;
}

Triangle.h//
// Created by User on 01.11.2016.
//
 
#ifndef PROST_TRIANGLE_H
#define PROST_TRIANGLE_H
 
 
#include <math.h>
#include "Line.h"
 
class Triangle {
public:
    Triangle(Line *line1, Line *line2);
    void expand(int a);
    double perimeter();
    double area();
    void printCalculated();
 
 
private:
    Line *_line1;
    Line *_line2;
    Line *_line3;
};
Triangle.cpp
#include <iostream>
#include "Triangle.h"
#include "Line.h"
#include "Point.h"
 
 
using namespace std;
 
Triangle::Triangle(Line *line1, Line *line2) {
    _line1 = line1;
    _line2 = line2;
    _line3 = new Line(_line1->p2(), _line2->p2());
 
}
void Triangle::expand(int a) {
 
    _line1->expand(a);
    _line2->expand(a);
 
 
 
 
}
double Triangle::perimeter() {
    cout<<_line1->lenght()<<endl;
    cout<<_line2->lenght()<<endl;
    cout<<_line3->lenght();
    return _line1->lenght() + _line2->lenght() + _line3->lenght();
}
 
double Triangle::area() {
 
}
 
void Triangle::printCalculated(){
    cout << "Perimeter = " <<perimeter() << endl;
    cout << "Area = " << area() << endl;
}
 
 
 
 
 
 
#endif //UNTITLED23_TRIANGLE_H

#include "Point.h"
#include "Line.h"
#include "Triangle.h"
 
 
 
int main() {
    Point p1(3, 0);
    Point p2(3, 3);
    Point p3(-1, 0);
 
 
    Line line1(&p1, &p2);
     line1.printLenght();
    Line line2(&p1, &p3);
 
 
    Triangle tr(&line1, &line2);
    tr.expand(2);
    tr.printCalculated();
    line1.printLenght();
 
 
    
 
    return 0;
}