How do you find angle B if in triangle ABC, angleA=41^@, AC=23, CB=12?

1 Answer
Dec 17, 2014

Use the law of sines, which is
a/(sin/_A) = b/(sin/_B)

The small a stands for the side opposite to /_A, which is CB.
The small b stands for the side opposite to /_B, which is AC.

Fill this in in the formula, then we get
12/(sin(41^∘)) = 23/(sin/_B)

By using cross-multiplication we find
sin/_B = (23*sin(41^∘))/12

By taking the inverse sine of the whole thing, we get:
/_B =sin^-1( (23*sin(41^∘))/12)