+128474 We can use the Law of Cosines to solve this
We have that
96.8^2 = 130^2 + 56^2 - 2(130)(56)cos(ABC) rearrange as
[ 96.8^2 - 130^2 - 56^2 ] / [ -2(130)(56)] = cos(ABC)
Using the cosine inverse (arccos), we have
arccos ( [ 96.8^2 - 130^2 - 56^2 ] / [ -2(130)(56)] ) = ABC ≈ 42.9°
