Isabelle proves that the triangles are congruent by using the parallel lines to determine a second set of angles are congruent. what statement and reason could she have used? ∠abc ≅ ∠bac; corresponding angles of parallel lines are congruent. ∠cab ≅ ∠dcb; alternate interior angles of parallel lines are congruent ∠abc ≅ ∠dcb; alternate interior angles of parallel lines are congruent ∠acd ≅ ∠abd; corresponding angles of parallel lines are congruent.