.
Answer by telling if each statement is Always, sometimes, or never true
1. If two distinct lines intersect, then they are parallel. <----- Never true.
2. If two distinct lines do not intersect, then they are parallel. <----- Always true.
3. If two angles are alternate interior angles, then they are on opposite sides of the transversal. <----- Always true.
4. If two parallel lines are cut by a transversal, then the alternate interior angles are congruent. <----- Always true.
5. If two parallel lines are cut by a transversal, then the alterate interior angles are complementary. <----- Never true.
6. If two parallel lines are cut by a transversal, then the corresponding angles are supplementary. <----- Always true.
See the lesson Parallel lines in this site.