The first statement is true because they have congruent angles.
The side length does not matter here because it's useless unless you're trying to find the perimiter of a triangle, which has a completely different algorithm. It is called the Pythagorem Theorum. I just learned the Pythagorem Theorum last class, and it isn't too difficult once you get the hang of it. Wow I went off course. Anyways I hope this helps!
