Trigonometry 7th Edition

Published by Cengage Learning
ISBN 10: 1111826854
ISBN 13: 978-1-11182-685-7

Chapter 7 - Section 7.2 - The Law of Cosines - 7.2 Problem Set - Page 378: 21

Answer

$A =39.52^\circ$ $B =83.85^\circ$ $C =56.63^\circ$

Work Step by Step

$\cos{A} = \dfrac{b^2+c^2-a^2}{2bc} = \dfrac{(75)^2+(63)^2-(48)^2}{2 \times 75 \times 63} = 0.771$ $$\therefore A = \boxed{39.52^\circ}$$ $\cos{B} = \dfrac{a^2+c^2-b^2}{2ac} = \dfrac{(48)^2+(63)^2-(75)^2}{2 \times 48 \times 63} = 0.107$ $$\therefore B = \boxed{83.85^\circ}$$ $$C = 180-(A+B) = 180-(39.52+83.85) = \boxed{56.63^\circ}$$
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.