C++ supports multiple inheritance unlike java. In multiple inheritance a class in C++ can have more than one class as it's parent class i.e., it can inherit property from more than one class.

            class Area        class Perimeter
                |                   |
                ---------------------
                         |
                  class Square

For example :

class Area
{
public:
    int area(int a)
    {
        return a*a;
    }
};

class Perimeter
{
public:
    int peri(int a)
    {
        return 4*a;
    }
};

class Square : private Area, private Perimeter
{
    private:
        int a;
    public:
       void get_data( )
       {
           cout<<"Enter length: ";
           cin>>a;
       }

       int area()
       {
                 return Area::area(a);
       }

       int peri()
       {
       return Perimeter::peri(area);
       }
};

int main()
{
    Square s;
    s.get_data();
    cout<<"Area = "<<s.area();
    cout<<"Perimeter = "<<s.peri();
    return 0;
}

OUTPUT :

Enter length: 5
Area = 25
Perimeter = 20

Note :Using multiple inheritance sometime leads the problem of ambiguity. For eg:

 
class A { virtual void add(); };
class B { virtual void add(); };
class C : public A ,public B { void add(); };

 
C c;
c.add();
A::add();  //this calls function of class A
B::add();  //this calls function of class B