C++ shape code

circle.cpp

#include "circle.h"
#include "shape.h"
#include <QString>
#include <cmath>
#include <QDebug>


using namespace std;
class circle: public shape

{
    double circle::area()
    {
        return(3.14*radius*radius);
    }

    QString getName()
    {
        return name;
    }

    QString getDimensions()
    {
        return dimensions;
    }

};

circle.h

#ifndef CIRCLE_H
#define CIRCLE_H
#include <QString>
#include <QDebug>


class circle: public shape
{
public:
    circle(double r): radius(r)
    {}

    double area();
    QString getName();
    QString getDimensions();

private:
    double radius;
};
#endif

main.cpp

#include <QtCore/QCoreApplication>
#include "shape.h"
#include "circle.h"
#include "rectangle.h"
#include "square.h"
#include <QString>
#include <iostream>
#include <cmath>
#include <QDebug>

using namespace std;

void showNameAndArea (shape * pshp)
{
    qDebug()<<pshp->getName()
           << " " << pshp->getDimensions()
           <<" area= " << pshp->area();
}

int main()
{

  rectangle rec(4.1,5.2);
  square squ(5.1);
  circle cir(6.1);

  qDebug() << "this program uses hierarchies for shapes";
  showNameAndArea(&rec);
  showNameAndArea(&cir);
  showNameAndArea(&squ);
  return 0;

};

rectangle.cpp

#include "rectangle.h"
#include"shape.h"
#include <QString>
#include <cmath>
#include <QDebug>
using namespace std;



class rectangle: public shape
{
    double Rectangle::area()
    {
        return(height*width);
    }

    QString getName()
    {
        return name;
    }

    QString getDimensions()
    {
        return dimensions;
    }

};

rectangle.h

#ifndef RECTANGLE_H
#define RECTANGLE_H
#include <QString>
#include <QDebug>



class rectangle: public shape
{
public:

    rectangle(double h, double w) :height(h),width(w)
    {}
    double area();
    QString getName();
    QString getDimensions();

protected:

    double height, width;


};
#endif

shape.cpp

#include "shape.h"
#include "circle.h"
#include "rectangle.h"
#include "square.h"
#include <QDebug>
#include <QString>
#include <iostream>
using namespace std;

shape::shape()
{

};

shape.h

#ifndef SHAPE_H
#define SHAPE_H
#include <QString>
#include <QDebug>

using namespace std;

class shape
{
public:



    virtual double area()=0;

    virtual QString getName()=0;
    virtual QString getDimensions()=0;

    virtual~shape(){}

};
#endif

square.cpp

#include "square.h"
#include "rectangle.h"
#include "shape.h"
#include <string>
#include <cmath>
#include <QDebug>
#include <QString>
using namespace std;

class square: public rectangle

{
    double square::area()
    {
        return(rectangle::area());
    }

    QString getName()
    {
        return name;
    }

    QString getDimensions()
    {
        return dimensions;
    }

};

square.h

#ifndef SQUARE_H
#define SQUARE_H
#include <QString>
#include <QDebug>

class square: public rectangle

{
public:

    square(double h): rectangle(h,h)
    {}

    double area();
    QString getName();
    QString getDimensions();

};

#endif