Answer:
∠B ≈ 18.95°
Step-by-step explanation:
The law of sines tells you ...
sin(B)/b = sin(A)/a
sin(B) = (b/a)sin(A) = (3/8)sin(120°) . . . . multiply by b; fill in the numbers
B = arcsin(3/8·sin(120°)) ≈ 18.95° . . . . use the inverse sine function
