Does angle of incidence=angle of reflection rule apply for diffused reflection also and how please demonstrate. 

Yes, the law of reflection always applies. That is, the angle of incidence = angle of reflection.

 

When light is incident on a rough surface, the reflected ray is diffused at a random angle as opposed to the case of regular reflection. But, if we see the surface closely, then the light ray incident at a particular point on the surface actually obeys law of reflection.

 

The figure below shows the case of diffused reflection. The normal to the surface is inclined at various angles and so are the reflected rays.