9514 1404 393
Answer:
∠B = 40° or 140°
Explanation:
The given angle is opposite the shortest of the given sides, so there are two possible solutions.
From the law of sines, ...
B = arcsin(b/a·sin(A)) = arcsin(9/7·sin(30°)) = arcsin(9/14)
Possible values for angle B are ...
B = arcsin(9/14) ≈ 40.0°
B = 180° -arcsin(9/14) ≈ 140.0°