Answer
α = 50.7°
Work Step by Step
using theorem 11.4.3 Law of cosine
cos α = $\frac{5^{2} + 9^{2} - 7^{2}}{2(5)(9)}$
cos α =$\frac{25 + 81 - 49}{90}$
cos α =0.6333
α = $cos^{-1}$(0.6333)
α = 50.7°
Elementary Geometry for College Students (7th Edition)
by Alexander, Daniel C.; Koeberlein, Geralyn M.
Published by
Cengage
ISBN 10:
978-1-337-61408-5
ISBN 13:
978-1-33761-408-5
Chapter 11 - Section 11.4 - Applications with Acute Triangles - Exercises - Page 528: 23
Update this answer!
You can help us out by revising, improving and updating this answer.
Update this answerAfter 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.
