Snell's law states that $n_1 \sin i = n_2 \sin r$ where $i$ is the angle of incidence, $r$ is the angle of incidence and the refractive index, $n = \frac{c}{v}$ where $v$ is the velocity of the light ray in the given medium.
I wonder how the $\sin$ comes into play and how one would derive it as I was only taught the formula and not the derivation in school. I welcome multiple proofs because I really want to understand why Snell's law works from multiple angles.
