How Do You Calculate Cos 125 Degrees in Engineering Mechanics?

AI Thread Summary
The discussion centers on calculating cos 125 degrees in an engineering mechanics problem. A participant questions the origin of the angle cos 125 degrees and the angle a=13.4 degrees. Another contributor suggests that the correct angle should be cos 135 degrees, derived from the calculation (180 - 15 - 30 = 135). This correction indicates a potential error in the original problem setup. Accurate angle identification is crucial for solving engineering mechanics problems effectively.
w4taup
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http://imageshack.us/f/560/engineeringmechproblem.jpg/

I have a question about this problem, i was wondering where they got the cos 125degrees as well as the a=13.4 degrees. If anyone knows how they got this answer can you please tell me how?
 
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w4taup said:
http://imageshack.us/f/560/engineeringmechproblem.jpg/

I have a question about this problem, i was wondering where they got the cos 125degrees as well as the a=13.4 degrees. If anyone knows how they got this answer can you please tell me how?
Looks like someone made an error. That should be cos 135 degrees (180 - 15 - 30 = 135) and the rest should follow.
 
lmfao thanks a lot bro, i was wondering for sooooo long how they got that :P
 
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