State laws of refraction.

Explanation

First law of refraction: The incident ray, the refracted ray of light and the normal to the refracting surface all lie in the same plane.
Second law of refraction: The ratio of the sine of the angle of incidence and sine of the angle of refraction is equal to refractive indices of the two media. This law is also known as Snell.s law.
`(Sin i)/(sin r) = (mu_(2))/(mu_(1))`