Geometry: Common Core (15th Edition)

Published by Prentice Hall
ISBN 10: 0133281159
ISBN 13: 978-0-13328-115-6

Chapter 3 - Parallel and Perpendicular Lines - 3-3 Proving Lines Parallel - Practice and Problem-Solving Exercises - Page 161: 16



Work Step by Step

The Converse of the Same-Side Interior Angles Postulate tells us the lines are parallel when the same-side interior angles are supplementary. The vertical angle to the angle marked $105^o$ and the angle marked $3x-18$ are same-side interior angles. $(3x-18)+105=180\longrightarrow$ definition of supplementary $3x+87=180\longrightarrow$ simplification $3x=93\longrightarrow$ subtraction property of equality $x=31\longrightarrow$ division property of equality
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.