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";
    }
}

#include <iostream>
 
class rectangle
{
protected:
    float a{};
    float b{};
    
public:
    rectangle()=default;
    rectangle(const float a, const float b):a(a),b(b){}
    float Perimeter(){return 2.0 * (a + b);}
};
 
class square :public rectangle
{
public:
    square()=default;
    square(const float a):rectangle(a,a){}
};
 
int main()
{
    float a{}; std::cout << "Input a side - > "; std::cin >> a;
    float b{}; std::cout << "Input b side - > "; std::cin >> b;
    
    rectangle r{a,b};
    square sq{a};
 
    std::cout << "Perimeter of Rectangle - > " << r.Perimeter() << std::endl;
    std::cout << "Perimeter of Square - > "    << sq.Perimeter() << std::endl;
}