Elementary Geometry for College Students (5th Edition)

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

Chapter 6 - Section 6.1 - Circles and Related Segments and Angles - Exercises - Page 286: 13b

Answer

measure of arc $AB=144^{\circ}$

Work Step by Step

The measure of a circle is $360^{\circ}$. Also, if two chords are congruent, then their arcs are congruent. Since $\overline{AB}=\overline{AC}$, their arcs are congruent. From part a we know that the measure of arc $BC=72^{\circ}$. Subtract the known arc from $360$, then divide the resulting number by 2 (for the two congruent arcs)... $360-72=288\div2=144$ measure of arc $AB=144^{\circ}$
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.