Light reflection and refraction diagrams with angle labels and terminology.

Problem Analysis:

The task involves labeling angles and identifying relationships in two diagrams related to the behavior of light. Let's break it down step by step.

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#### Diagram 1:
This diagram shows a ray of light reflecting off a flat surface (mirror). The key concepts here are:
- Incident ray: The incoming ray of light.
- Reflected ray: The outgoing ray of light after reflection.
- Normal: An imaginary line perpendicular to the surface at the point of incidence.
- Angle of incidence: The angle between the incident ray and the normal.
- Angle of reflection: The angle between the reflected ray and the normal.

From the diagram:
- Angle 1 is the angle between the incident ray and the normal.
- Angle 2 is the angle between the reflected ray and the normal.

According to the Law of Reflection:
$$
\text{Angle of incidence} = \text{Angle of reflection}
$$

Thus, Angle 1 is equal to Angle 2.

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#### Diagram 2:
This diagram shows a ray of light passing through a glass block. The key concepts here are:
- Incident ray: The incoming ray of light entering the glass block.
- Refracted ray: The ray of light as it bends upon entering the glass block.
- Emergent ray: The ray of light as it exits the glass block.
- Normal: An imaginary line perpendicular to the surface at the point of incidence or emergence.
- Angle of incidence: The angle between the incident ray and the normal.
- Angle of refraction: The angle between the refracted ray and the normal.

From the diagram:
- Angle 1 is the angle between the incident ray and the normal at the first surface.
- Angle 2 is the angle between the refracted ray and the normal inside the glass block.
- Angle 3 is the angle between the refracted ray (inside the glass) and the normal at the second surface.
- Angle 4 is the angle between the emergent ray and the normal at the second surface.

According to the Law of Refraction (Snell's Law):
$$
n_1 \sin(\theta_1) = n_2 \sin(\theta_2)
$$
where \( n_1 \) and \( n_2 \) are the indices of refraction of the two media, and \( \theta_1 \) and \( \theta_2 \) are the angles of incidence and refraction, respectively.

However, for this problem, we are only asked to identify which angles are equal. From the diagram:
- Angle 1 is the same as Angle 4 because the light ray re-emerges at the same angle it entered due to symmetry and the reversibility of light paths.
- Angle 2 is the same as Angle 3 because the light ray follows the same path in reverse when exiting the glass block.

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Solution:

#### Diagram 1:
- Angle 1 is *equal to* angle 2.

#### Diagram 2:
- Angle 1 is the same as *Angle 4*.
- Angle 2 is the same as *Angle 3*.

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Final Answer:

$$
\boxed{\text{Diagram 1: Angle 1 is *equal to* angle 2. Diagram 2: Angle 1 is the same as *Angle 4*, Angle 2 is the same as *Angle 3*.}}
$$