Using virtual destructors gives error

I'm making a little program for school. I want to add virtual destructor to the class 'IObject', 'Square' and 'RotatedSquare'. But when I do, it gives an error. Is it not possible in this case or how to do it here? here's my code:

interface iobject :

#ifndef IOBJECT_H_
#define IOBJECT_H_
#include "Point.h"

class IObject {
public:
    virtual const Point& getPosition()const = 0;
    virtual double getSize()const = 0;
    //virtual ~IObject();

};

#endif

class square

#ifndef SQUARE_H_
#define SQUARE_H_
#include "IObject.h"
#include "Point.h"
#include <iostream>
class Square : public IObject{
private:
    Point position;
    double size;
public:
    Square(const Point& position, const double size):position(position),size(size){};
    virtual const Point& getPosition() const {return this->position;}
    virtual double getSize() const {return this->size;}
    friend std::ostream& operator<<(std::ostream& out, const Square& s);
    //virtual ~Square();

protected:
    virtual void print(std::ostream& out) const;
};

#endif 

class RotatedSquare

#ifndef ROTATEDSQUARE_H_
#define ROTATEDSQUARE_H_
#include "Square.h"

class RotatedSquare : public Square{
private:
    double angle;
public:
    RotatedSquare(const Point& position, const double size, const double angle): Square(position,size),angle(angle){};
    double getAngle() const {return this->angle;}
    //virtual ~RotatedSquare();
protected:
    virtual void print(std::ostream& out) const;
};

#endif

the error :

Undefined symbols for architecture x86_64:
  "Square::~Square()", referenced from:
      _main in Practice.o
  "vtable for RotatedSquare", referenced from:
      RotatedSquare::RotatedSquare(Point const&, double, double) in Practice.o
  NOTE: a missing vtable usually means the first non-inline virtual member function has no definition.
  "vtable for Square", referenced from:
      Square::Square(Point const&, double) in Practice.o
  NOTE: a missing vtable usually means the first non-inline virtual member function has no definition.
  "vtable for IObject", referenced from:
      IObject::IObject() in Practice.o
  NOTE: a missing vtable usually means the first non-inline virtual member function has no definition.

the main class :

#include <iostream>
#include "Point.h"
#include "IObject.h"
#include "Square.h"
#include "RotatedSquare.h"

int main() {

     IObject* s1 = new Square(Point(1,4),2.2);
     std::cout << s1->getPosition() << std::endl;
     std::cout << s1->getSize() << std::endl;
  Square s2 = Square(Point(4,5),5);
  Square* s3 = new RotatedSquare(Point(5,5),8,60);
  std::cout << s2 << std::endl;
  std::cout << *s3;
return 0;
}

via Chebli Mohamed