Posted by Louis on .
I'm in gr 11 doing Trigonometry
14.2 = b
 
sin38 sin 67
a = 46
 
sin20 sin130
(10.7)^2 = (9.5)^2 + (12.4)^2  2(9.5)(12.4) cos <B
I just need someone to explain this to me because I just don't get it... thank you for any help

Math 
bobpursley,
You are dealing with the law of sines and cosines. I am not certain what you don't get. Is it the algebra?
1) b=14.2*sin67 / sin38 put these in the calculator and compute.
2) Same issue:
a= 46*sin20/sin130
3) Law of cosines:
cosB= ((10.7)^2  (9.5)^  (12.4)^2 )/[(9.5)(12.4)]
Then to find angle B, take the inverse cosine of that result.
If you have questions, ask.