Answer:
C. Of the Corresponding Angles Postulate.
Step-by-step explanation:
We have been given a diagram, in which line segment AB is parallel to segment CD. We are asked to choose the reason that states that angle 1 is congruent to angle 2.
Let us see line BC as a transversal.
Since alternate interior angles are equal, therefore, measure of angle DCB is equal to angle ABC.
Let us see line BC as a transversal.
Since alternate interior angles are equal, therefore, measure of angle BAD is equal to angle CDA.
Since angle 1 corresponds to angle 2, therefore, angle 1 is congruent to angle 2 because of the Corresponding Angles Postulate..