Elementary Geometry for College Students (5th Edition)

Published by Brooks Cole
ISBN 10: 1439047901
ISBN 13: 978-1-43904-790-3

Chapter 2 - Section 2.3 - Proving Lines Parallel - Exercises - Page 91: 20

Answer

1. By the definition of angle bisector, if CE bisects angle BCD and if BE bisects angle ABC, then angle 1 equals angle two, and angle 3 equals angle 4. 2. Thus, because angle 2 and angle 3 add up to 90 degrees, this means that angle ABC and BCD add up to 180 degrees. 3. If corresponding angles are congruent, it follows that angle BCD is congruent to angle ABC's supplement. 4. Thus, if the corresponding angles are congruent, then ABC and BCD are supplementary. 5. ABC and BCD are supplementary as found in (2), so corresponding angles are congruent. 6. If corresponding angles are congruent, the two lines are parallel. 7. l and n are parallel.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.