The mirror's reflection of light obeys the law of reflection, its reflectivity depends on the angle of the incident light, the smoothness of the mirror and the nature of the metallized metal film. The imaginary line perpendicular to the mirror is called the normal, the angle between the incident line and the normal and the angle between the reflected line and the normal are equal. The object in front of the mirror is an upright virtual image behind the mirror. The distance between the mirror and the mirror is the same as the distance between the mirror and the mirror. If you want to see my whole length from the mirror, because the angle of incidence is equal to the angle of reflection, the mirror must have at least half of my length. The reflective surface of the concave mirror faces the center of curvature.