Answer: Choice C. Angle Y = Angle B
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Explanation:
ASA stands for "angle side angle".
To use ASA, we must have two pairs of congruent angles, as well as a pair of congruent sides. The sides must be between the angles in question.
So far we're given
The thing we're missing is the other pair of congruent angles. So the missing congruent pair of angles is Angle Y = Angle B as those two angles are adjacent to the segments mentioned above.
Something like angle A is not adjacent or touching segment CB. Also, angle X is not adjacent to segment ZY. So we can rule these angles out. We'd only use these angles if we were dealing with AAS instead of ASA.
