Basic OOP

#include<iostream>
#include<string>

using namespace std;

class Point
{
private:
    double x;
    double y;

public:
    Point();
    Point(double first, double second);

    double getX();
    double getY();
    void display();
    ~Point();
};

Point::Point(void)
{
    x = 0.0;
    y = 0.0;
}

Point::Point(double first, double second)
{
    x = first;
    y = second;
}
Point::~Point(void)
{

}

double Point::getX(void)
{
    return x;
}

double Point::getY(void)
{
    return y;
}

void Point::display()
{
    cout << "(" << x << ", " << y << ")" << endl;
}

class Line
{
private:
    double offset, slope;

public:
    Line();
    Line(Point P1, Point P2);

    bool isPerpendicularTo(Line l);
    void display();
    ~Line();
};

Line::Line(void)
{
    offset = 0.0;
    slope = 1.0;
}

Line::Line(Point p1, Point p2)
{

}

void Line::display()
{
    cout << "y = " << slope << "x + " << offset << endl;
}

///If multiplication of 2slope of 2line equal to -1
bool isPerpendicularTo(Line l)
{

}

int main()
{
    Point P1(1.0, 2.0), P2(3.0, -3.0), P3(0.0,1.0), P4(10.0, 5.0);

    Line L1(P1, P2);
    L1.display();
    cout << endl;

    Line L2(P3, P4);
    L2.display();
    cout << endl;

    if(L1.isPerpendicularTo(L2)){
        cout << "Line ";
        L1.display();
        cout << " is perpendicular to Line ";
        L2.display();
        cout << "." << endl;
    }
    else{
        cout << "Line ";
        L1.display();
        cout << " is NOT perpendicular to Line ";
        L2.display();
        cout << "." << endl;
    }

    return 0;
}