Solve triangle ABC if <A=x=45.8, b=12.3, c=14.5

Question

Using the law of cosine and find:

x=

<B=

<C=

Can someone explain me how I can find b?

I found x with the law of cosine and got 10.62. When looking for b I used again the law of cosine (as explained in the exercise), and since I'm looking for the angle I used the formula of CosB(a^2+ c^2 - b^2) /2ac but I got error in the computer. Tried the law of sine with 10.62/Sin(45.8)=12.3/Sin(b) and the answer didn't work.

Answer 1

Your answer for x is correct. Using the Law of Sines like you did works. Be careful when plugging into the calculator/computer. When you multiply sin 45.8 times 12.3, first enter sin 45.8 then hit enter.and then multiply by 12.3. Hit enter again and then divide by 10.6. Finally do the inverse sin of your anwer. I got Angle B = 56.3. Hope this helps!