# Prove that sina'=nsinb

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1. May 19, 2016

### annalian

1. The problem statement, all variables and given/known data
look at the figure and prove that sina'=nsinb. We have given a, b, a', b' and n
http://s32.postimg.org/n7rnu0khx/image.png

2. Relevant equations
sinb'/sina'=1/n

3. The attempt at a solution
But in the equation we have b, not b'. I made the figure. How would the correct one be?

2. May 19, 2016

### RUber

Can you prove that $\sin b = \sin b'$?

3. May 19, 2016

### annalian

No, only if the triangle has 2 equal sides

4. May 20, 2016

### RUber

Are the dashed lines making a and a' forming right angles with the sides of the triangle?