What can you tell about the mean of each distribution iready

I'm confused on this could anyone me and show me what i need to do to solve it.

Segment an is an altitude of right δabc with a right angle at a. if ab = 2, squared 5 in and nc = 1 in, find bn, an, ac.

Which sum or difference identity would you use to verify that cos (180° - q) = -cos q? a.) sin (a -b) = sin a cos b – cos a sin b b.) cos (a -b) = cos a cos b – sin a sin b c.) cos (a -b) = cos a cosb + sin a sin b d.) sin (a + b) = sin a cos b + cos a sin b