In triangle ABC use the sine law.
Similarly for the triangle ADC:
Given two right angle triangles sharing a common side AC.
Call them ABC, and ADC.
First triangle angle ACB is
angle ABC is a right angle.
Second triangle angle CAD is
angle ADC is a right angle.
Why is the following statement true.
I don't see how this can hold when
I tried using pythagoras, but that doesnt' work.
Perhaps I am missing something about the angle of refraction.