Answer:
∠ B = 119°
Step-by-step explanation:
∠ C and 112° are adjacent angles and supplementary, thus
∠ C = 180° - 112° = 68°
The external angle of a triangle is equal to the sum of the 2 opposite interior angles.
∠ B is an exterior angle of the triangle, thus
∠ B = 51° + ∠ C = 51° + 68° = 119°
