Mirror reflection of light is subject to the law of reflection, the reflection ability depends on the angle of the incident light, the smoothness of the mirror and the properties of the metal coating. The imaginary line perpendicular to the mirror is called the normal, and the angle between the incoming ray and the normal and the reflection line are equal to the angle of the normal. The object in front of the planar mirror becomes a positive imaginary image after the mirror, and the distance from the mirror is equal to the distance between the object and the mirror. If you want to see my whole body length from the mirror, because the incident angle is equal to the reflection angle, the mirror must have at least half of my body length. The reflector of the concave mirror faces toward the center of curvature.