Elementary Geometry for College Students (7th Edition) Clone

Published by Cengage
ISBN 10: 978-1-337-61408-5
ISBN 13: 978-1-33761-408-5

Chapter 2 - Section 2.4 - The Angles of a Triangle - Exercises - Page 105: 4

Answer

$m∠A=m\angle C =69^{\circ}$

Work Step by Step

we know sum of all three angles of triangle is $180^{\circ}$ $m∠A+m∠B+m∠C$=$180^{\circ}$ $m\angle A+42^{\circ}+m\angle C$ = $180^{\circ}$ $m∠A+m\angle C $= $180^{\circ}−42^{\circ}$ $m∠A+m\angle C $ = $138^{\circ}$ $m∠A=m\angle C= 138^{\circ}\div2 =69^{\circ}$
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.