In high school (and I truly hate to be the one to tell you this), it is quite possble that your teacher doesn't know the answer, so he is annoyed at you for asking questions so that you do not expose his/her shortcomings.
A lot of high school teachers know little past what they are actually teaching and even that not in a lot of depth. This is for a lot of reasons, some of them not their fault, but it is a sad fact.
So, keep asking and keep annoying them. Try going and asking during their office hours, but don't be surprised if you do not get a satisfactory answer and if it does not seem satisfactory, I would question its validity.