# Thread: Could you please explain these pythagoras equations?

2. ## Re: Could you please explain these pythagoras equations?

Those aren't "Pythagorean" equations (though they are related) because these are not right angles. This is the
"cosine law". If a triangle (right triangle or not) has side lengths of "a", "b", and "ac", with angle "C" opposite the side of length "c" then $c^2= a^2+ b^2- 2ab cos(C)$.