a) no solutions
b) B = 49.8° or 130.2°
a) By the law of sines, ...
... sin(B)/b = sin(A)/a
... sin(B) = b·sin(A)/a = (11/9)·sin(61°) = 1.069 . . . . . not realizable
there is no solution
b) As before, ...
... sin(B) = (28/25)·sin(43°) ≈ 0.763838...
... B = arcsin(0.763838...) ≈ 49.80°
The side length b is longer than the side length a, so there will be two solutions. The other angle for B is the supplement to this one:
... B = 180° -49.8° = 130.2°