Geometry: Common Core (15th Edition)

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

Chapter 1 - Tools of Geometry - 1-5 Exploring Angle Pairs - Practice and Problem-Solving Exercises: 39

Answer

Both are correct.

Work Step by Step

The definition of an angle bisector tells us that: $m\angle ABX=m\angle CBX$ The angle addition postulate tells us that: $m\angle ABX+m\angle CBX=m\angle ABC$ Substitute: $m\angle ABX+m\angle ABX=m\angle ABC$ Combine like terms: $2m\angle ABX=m\angle ABC\longrightarrow$ one student is correct Divide each side by 2: $2m\angle ABX\div2=m\angle ABC\div2$ $m\angle ABX=\frac{1}{2}m\angle ABC\longrightarrow$ the other student is also correct
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.