The normal is perpendicular to the reflecting surface at the point where an incident ray arrives. The angle of incidence equals the angle of reflection; measure both from the normal rather than the surface. A smooth surface gives specular reflection, while varied local normals on a rough surface scatter the rays. Each reflected ray obeys the same law. Use arrows to show the direction in which light travels. Use clear labels. Check your reasoning. Explain why the chosen model fits this situation.