Usually it is one law of refraction , but sometimes it can be divided into two or three parts .
Expressed in one sentence , the law essentially says :
If or when a light ray is reflected on a smooth surface or a mirror , the reflected ray, and the normal to the smooth surface ( or to the surface of the mirror) all lie in the same plane, and the angle of reflection is equal to the angle of incidence .
Here is another expression of the law , in three parts or divided into three laws :
1)If the reflecting surface is very smooth, the reflection of light that occurs is called specular or regular reflection. The laws of reflection are as follows:
2)The incident ray, the reflected ray and the normal to the reflection surface at the point of the incidence lie in the same plane.
3)The angle which the incident ray makes with the normal is equal to the angle which the reflected ray makes to the same normal.
The reflected ray and the incident ray are on the opposite sides of the normal.