Как передать записанные значение базового класса в дочерний класс

 rectangle.h
#pragma once
 
class rectangle
{
protected:
    float a, b;
public:
    rectangle(void);
    ~rectangle(void);
    rectangle(float, float);
    float PerimRect() {
        return 2.0 * (a + b);
    }
    void input();
};

 rectangle.cpp
#include "rectangle.h"
#include <iostream>
#include <math.h>
 
using namespace std;
 
rectangle::rectangle(void) : a(0), b(0) {}
 
rectangle::rectangle(float A, float B) : a(A), b(B) {}
 
rectangle::~rectangle(void) {}
 
void rectangle::input() {
    cout << "Input a side - > ";
    cin >> a;
    cout << "Input b side - > ";
    cin >> b;
}

 square.h
#pragma once
#include "rectangle.h"
 
class square :
    public rectangle
{
public:
    square(void);
    ~square(void);
    float PerimSqr() {
        return 4.0 * a;
    }
};

 square.cpp
#include "square.h"
#include <iostream>
 
using namespace std;
 
square::square() : rectangle(a, b) {}
 
square::~square(void) {}

 reshenie.cpp
#include "rectangle.h"
#include "square.h"
#include <iostream>
 
using namespace std;
 
int main() {
    rectangle reshenobj;
    square reshobj;
    reshenobj.input();
    //reshobj.input();
    cout << "Perimeter of Rectangle - > " << reshenobj.PerimRect() << endl;
    cout << "Perimeter of Square - > " << reshobj.PerimSqr() << endl;
    if (reshenobj.PerimRect() > reshobj.PerimSqr()) {
        cout << "Perimeter of Rectangle more bigger than Square";
    }
    else {
        cout << "Perimeter of Square more bigger than Rectangle";
    }
}

class interface{
   virtual void DoIt() =0;
   ~interface(){};
}

Rectangle sq{a,a};

#include <iostream>
#include <vector>
#include <memory>
using namespace std;
struct Rectangle{
    int a{},b{};
    int area(){return a*b;};
    Rectangle(int a, int b):a{a},b{b}{}
    double SidesRatio(){ return max(a,b)/min(a,b);}
    virtual void Print(){cout<<a<<' '<<b;};
    virtual ~Rectangle(){}
};
struct Square : public Rectangle{
    Square(int a):Rectangle{a,a}{}
    virtual void Print(){cout<<a;};
    virtual ~Square(){}
};
int main()
{
    vector<unique_ptr<Rectangle>> all_figure;
    all_figure.emplace_back(make_unique<Rectangle>(2,6));
    all_figure.emplace_back(make_unique<Square>(2));
    for(auto & f : all_figure){
        cout << "area = " << f->area() << endl;
        cout << "SidesRatio = " << f->SidesRatio() << endl;
        f->Print();
        cout << endl << endl;
    }
    return 0;
}