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 .
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Below is an illustration of the law of reflection , the refracted ray is also shown (image source : File:Ray optics diagram incidence reflection and refraction.svg ) :
Here is another expression of the law , in three parts or divided into three laws :
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:
- The incident ray, the reflected ray and the normal to the reflection surface at the point of the incidence lie in the same plane.
- 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.