Originally Posted by

**Fnus** Alright, so I have this right-angled triangle and I thought I did it right, but apparently I didn't, so any help would be great appreciated!

I wanted to find B,

So I just used b / SinB = c /sinC

SinB = b / c

SinB = sin^-1(38/63)

I end up with 37.1, but the answers said I wanted 52.9!

So I switched the sin^-1 for a cos^-1, and I ended up with 52.9. ):

Now my question is, why do I want to use cos instead of sin?

I really don't get it! I can't see why it's wrong to use sine since since is Opposite/Hypothenuse.

Thanks in advance!