This is the reflected ray. Put an arrow on it to show its direction. The law of reflection states that: angle of incidence i = angle of reflection r. For example, if a light ray hits a surface ...

Schematic of a grazing incidence small and wide angle X-ray scattering (GISAXS/GIWAXS) experimental setup showing the incident (αi) and the scattered angles along the horizontal (2θf) and vertical (αf ...