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## Homework Statement

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)

## Homework Equations

c^2 = a^2 + b^2 - 2ab(cosC)

## 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!