access base class with address of child in c++

#include<iostream>
#include<conio.h>
using namespace std;
class base
{
public:
       void base_Cls()
      {
           cout << "this is base class"<< endl;
           }     
};
class child: public base
{
public:
       void child_Cls()
       {
            cout << "this is child class";
            }     
};
int main()
{
    base *b;
    child ch;
    b=&ch;
    b->child_Cls();
    getch();
   
    }