1. The problem statement, all variables and given/known data Ok so I am having difficulty doing significant digits for longer operations (i.e. cosine law) where you also have square roots and squares (I know they are simply multiplications) 2. Relevant equations c^2 = a^2 + b^2 - 2ab(cosC) 3. The attempt at a solution Here are some example numbers. Please let me know if the answer is in correct significant digits. c^2 = 22^2 + 65^2 - 2(22)(65)(cos119degrees) , c greater than or equal to 0 c=78 I think for cosine law what is really confusing me is how the cos119 converts into a very long decimal (weird fraction results) And what about for sine law? example sin 119 degrees / 78.08 = sin theta / 65 theta = 47 degrees Are the significant digits for both answers correct? Please help!