Answer:
BA ≅ BC
Explanation:
calculate the measure of the third angle in the triangle.
∠ A = 180° - (66 + 57)° = 180° - 123° = 57°
Then
∠ A = ∠ C = 57°
thus the triangle is isosceles with legs opposite the equal angles being congruent, that is
BA ≅ BC