# Math Help - Sine Law

1. ## Sine Law

I'm required to figure out an angle for part of one of my physics questions. Got this so far:

Sin C / c = Sin B / b
Sin 40 / 27.83 = Sin B / 20
(0.6428) / 27.83 = Sin B / 20
(0.6428)(20) = (27.83)(Sin B)
12.586 = 27.83(Sin B)
[12.586 = 27.83(Sin B)] / 27.83
0.4620 = Sin B

I've gotten up to here so far. Though, I have no idea what to do next. Is 0.4620 my answer (angle of 46 degrees), or do I still have to do something with Sin B?

2. Originally Posted by shadow6

Sin C / c = Sin B / b
Sin 40 / 27.83 = Sin B / 20
$\frac{\sin 40}{27.83} = \frac{\sin B}{20}$

$\frac{20\sin 40}{27.83} = \sin B$

$\sin B=\frac{20\sin 40}{27.83}$

$B=\sin^{-1}\left(\frac{20\sin 40}{27.83} \right)$

3. Tyvm.