The angle of reflection is the angle the to the reflecting surface.
reflected rays make with a perpendicular line
instant raise makes with a perpendicular line
instant ray makes with a parallel line
reflected ray mix with a parallel line

The angle of reflection is the angle the reflected rays make with a perpendicular line to the reflecting surface.  

Explanation:

Reflection It is the change of direction suffered by a luminous ray when hitting the surface of an object. The angle of reflection is that which is formed by the reflected ray and the normal vector to the study surface

the word that best describes martin luther king jr.'s tone in the video is dignified

martin luther king, jr. was a social activist and baptist minister who played a key role in the american civil rights movement from the mid-1950s until his assassination in 1968. the video shows his manner and attitude having or showing a composed or serious manner that is worthy of respect so dignified is the correct answer