Question

In ΔSTU, s = 3.8 inches, t = 9.8 inches and u=9.6 inches. Find the measure of ∠U to the nearest 10th of a degree.

Answer 1

m∠U = 75.7°

Explanation:

its on delta and if you use a calculator then its m∠U = 75.7°

Answer 2

m∠U = 75.7°

Explanation:

use Law of Cosines:

9.6² = 3.8² + 9.8² - 2(3.8)(9.8)·cos U

92.16 = 14.44 + 96.04 - 74.48·cos U

92.16 = 110.48 - 74.48·cosU

-18.32 = -74.48·cosU

cos U = -18.32/-74.48

cos U = 0.24597

arccos U = 75.7