Answer:
A. 42.5
Explanation:
The triangle shown is an isosceles triangle. An isosceles triangle haas two of its sides and base angles equal. Hence;
<ACB = <ABC (Base angles are equal)
Given
<ACB = 42.5°
Required
<ABC
According to the law above which says <ACB = <ABC , hence <ABC is also equal to 42.5°