You have your angle measurement set to radians (which is default) and I believe one was measured in radians while another was measured in degrees. If that isn't it then it could be that the first angle was from horizontal to the pillar whilst the second angle was from vertical to the pillar. Pretty sure the problem is one of the two.
I thought I solved it by substracting 60.642 from 90 which is 29.358. That clearly makes more sense here but it somehow still doesn't line up perfectly. There is still that tiny difference. What would be the correct angle in your opinion?