Solve SSA:
B=12.1 degrees b= 15 a= 23.9
This is the ambigious case, there are 2 cases possible
sinA/23.9 = sin 12.1/15
sinA = .33399
angle A = 19.5° or 160.5°
case1:
A = 19.5, B=12.1, then C=148.4
c/sin148.4 = 15/sin12.1
c = 37.5
case2:
A= 160.5, B=12.1, then C = 7.4°
c/sin7.4 = 15/sin12.1
c = 9.23