Given a right triangle ABC with a=13 and b=26, find the value of angle A, angle B, and side length c. Round to the nearest thousandth.

I will assume that neither A nor B are the right angle, or else why would you ask to find it

So tanB = 13/26 = 1/2
angle B = 26.565
then angle A = 63.435° (90 - B)

c^2 = a^2 + b^2 = ...
you finish it