Carlos draws a transversal, t, on two parallel lines ab and cd, as shown below: two parallel lines are shown cut by a transversal labeled t. 1, 2, 7 and 8 are marked clockwise as exterior angles. 4, 3, 6, and 5 are marked clockwise as interior angles he makes the following table to prove that the alternate interior angles are equal: statement justification angle 1 = angle 5 corresponding angles of parallel lines are congruent. angle 1 = angle 3 ? angle 3 = angle 5 transitive property of equality, angle 1 = angle 5, angle 1 = angle 3, therefore angle 3 = angle 5 which is the missing justification?