Multiple Inheritance Question

[Alexandros81]

Hi! Never done multiple inheritance in the past and it is been asked
from my tutor to do so.
I have developed a code after request that follows:

  #include <iostream>
using namespace std;

class Polygon {
    protected:
        int width, height;
    public:
        void set_values (int a, int b)
        { width=a; height=b;}
};

class Rectangle: public Polygon {
    public:
        int area ()
        { return width * height; }
};

class Triangle: public Polygon{
    public:
        int area ()
        {
            return (width*height)/2;
        }
};

int main () {
    Rectangle rect;
    rect.set_values (5,8);
    cout << "Emvadon orthogoniou: " << rect.area() << '\n';
    Triangle tria;
    tria.set_values(6,4);
    cout << "Emvadon trigwnou: " << tria.area() << '\n';

    return 0;
}

It is been asked to add class PaintCost in the above code and make the appropriate changes so that class Rectangle is a descendant of PaintCost also.

Here is PaintCost:

class PaintCost
{
public:
int getCost(int area)
{
return area * 70;
}
};

Also add in main the appropriate statements that show message "Overal paint cost: ..."

thanks

[Moschops]

class Rectangle: public Polygon, public PaintCost {
    public:
        int area ()
        { return width * height; }
};