Aray diagram is shown.
what does the letter x represent?

angle of incidence
angle of reflection
normal
medium

Angle of incidence

Explanation:

The diagram shows the reflection of a light ray.

When a light ray undergoes reflection:

- The incident ray, the reflected ray and the normal to the surface all lie in the same plane

- The angle of reflection is equal to the angle of incidence

The two angles are defined as follows:

- The angle of incidence is the angle between the incident ray and the normal to the surface (1)

- The angle of reflection is the angle between the reflected ray and the normal to the surface

In the picture, we see that the angle marked with X corresponds to the angle defined in (1), so it is the angle of incidence.

layers of the earth affect the waves and these effects are seen on instruiments such as seimometers

answer and explanation;