Geometry Assignment 3.4 Name: Period: Proving Lines are Parallel Date: Give the choice or choices that make the statement true. 14. If two parallel lines are cut by a transversal, then the alternate interior angles are (always, sometimes, never) congruent, and (always, sometimes, never) supplementary. 15. If two parallel lines are cut by a transversal, then the same side interior angles are (always, sometimes, never) congruent, and (always, sometimes, never) supplementary. 16. If two lines are cut by a transversal so that alternate interior angles are (congruent, supplementary, complementary), then the lines are parallel. 17. If two lines are cut by a transversal so that consecutive interior angles are (congruent, supplementary, complementary), then the lines are parallel. 18. If two lines are cut by a transversal so that (alternate interior, alternate exterior, corresponding) angles are congruent, then the lines are parallel. Given: line m and line n are parallel m 3 6 19. 41 and 44 are (always, sometimes, never) congruent, and (always, sometimes, never) supplementary. 20. 44 and 45 are (always, sometimes, never) congruent acute angles, (always, sometimes, never) congruent obtuse angles, and (always, sometimes, never) be congruent 90 degree angles. 21. If line r were perpendicular to line m, then all of the angle measures would (always, sometime, never) be 90 degrees. 22. Complete the two-column proof. Given: 8 1| m, 41 = 42 Prove: a ll b Statements Reasons 1. em 1. Given 2. 21 = 13 2. sanspending angles 3. 21 = 22 3. Given 4, 42 = 23 4. Substitution 5, ab 5. AEA