A mirror is a device that contains a surface that reflects light. $^4$
They do not absorb much light, and most of the light that hits it is redirected (reflected) in accordance to the law of reflection.$^4$ $^1$
The law of reflection states that when a light ray incidents a surface, the angle between the incident ray and the normal is equal to the angle between the reflected ray and the normal.$^5$
$$ \theta_i = \theta_r $$
The normal is a perpendicular line to the surface.
The incident ray is the ray that is hitting the surface.
The reflected ray is the ray that is created after reflecting off of the surface.
When the mirror is a curve, the normal is calculated as the perpendicular line to the tangent of the surface.
There are three types of mirrors(that this text covers):$^1$
The pole of the mirror is the geometric center of the mirror.
Reflecting surface is the side of the mirror that is reflective.
Painted surface is the side of the mirror that is not reflective.
