SAS with Laws of Sine and Cosine
Hello. I had to solve the following triangle using Law of Sines / Cosines:
b = 6
c = 13
alpha = 16 degrees
The first time I solved the triangle, I first used the law of cosines and got
a = 7.42
I then used the law of sines to solve for beta and got 12.9 degrees. (beta = sin inverse of 6 sin 16 / 7.42)
I then used 180 - (16 + 12.9) and found gamma to be 151.1 degrees.
I then solved the triangle a second time, but instead of solving for the beta angle using the law of sines, I solved for gamma.
In that case, I found that gamma was equal to 28.8 degrees. (gamma = sin inverse of 13 sin 16 / 7.42) This would then make beta equal to 135.2 degrees.
I read that I'm supposed to solve for the smaller angle first using the law of sines. Can solving for the larger angle first cause such a wide variation in the answer, or did I incorrectly solve for the larger angle?