First, illustrate the problem, enumerate what is given:
83.23 degrees = angle formed by two stars
33 light years = distance from E to A
21 light years = distance from E to B
Use the cosine law to solve for the distance between two stars:
The opposite side of the angle 83.23 degrees is the distance between star A and star B.
D^2 = A^2 + B^2 - 2ABcos (x)
D^2 = 33^2 + 21^2 - (2*33*21*cos(83.23))
solve for D
D = 36.97 light years
Therefore, there are 36.97 light years between star A and star B.