Hi,

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.