C++: hide method from children

I have a class called transform, and its child classes, translation, rotation and scaling, which are supposed to apply transformations on a triangle.

Each of the child classes overrides the apply_transform() method:

class transform
{
protected:
    virtual triangle apply_transform(const triangle&) const = 0;
public:
    static triangle apply_transforms(const triangle&, const std::initializer_list<const transform*>&);
};

class scaling : public transform
{
...
public:
    triangle apply_transform(const triangle&) const override;
};

//same for rotation and translation

I also have a function called apply_transforms, which should be accessible to the outside world, and I use it to apply multiple transformations. I pass it a list of transform* to enable polymorphism.

The only issue I have is that now, the child classes are also aware of this method. This is bothering me since a child class shouldn't be able to apply all of the other transformations.

Is there an elegant solution to this?

Make apply_transforms a non-member function that is not included into header files required by classes implementing transform.