Please explain me the Laws of Reflection?

I will add one more point for better understanding. Light ray always follows the path for which least time is required, that is, the path taken between two points by a ray of light is the path that can be traversed in the least time. This is called Fermat's Principle. A good analogy can be drawn to a situation where a crow is sitting on a tree, some food grains are lying on the ground and few hunters are waiting for the crow to fly down to the grains so that they can hunt it. There is another tree just opposite to the one on which the crow is sitting. What should the crow do? It should fly down to the grains as fast as possible, take a mouthful of them in an instant and fly up to the top of the other tree as soon as possible. Since throughout its journey the crow is in the same medium (air), its speed is same and so to minimize the time of action, it must minimize the total length of its path. Just draw the two situations: one when the crow's angle of incidence and angle of reflection are equal, and the other when they are unequal. Check that the least distance is travelled (and hence the least time is required) if the crow follows the first path (you will need some triangle congruency theorems to show this.) And this is the first law of reflection. And yes, there is a third law of reflection which is missing in nearly all textbooks that I have seen, that is, the incident and the reflected ray are on the opposite sides of the normal. read less