Reason 1. AB is congruent to DC - given
Reason 2. AB is parallel to DC - given
Reason 3. angle BAC is congruent to angle DCA - alternate interior angles are congruent
Reason 4. AC is congruent to AC - reflexive property of congruence
Reason 5. triangle ABC is congruent to triangle CDA - Side Angle Side
AC is congruent to AC - reflexive property of congruence
