Answer:
∠ U ≈ 93.6°
Step-by-step explanation:
using the Law of Cosines
• cos U = \(\frac{v^2+w^2-u^2}{2vw}\)
u, v , w are the sides opposite ∠ U, ∠ V and ∠ W , respectively.
here u = 14 , v = 11 , w = 8
substitute these values into the formula for cos U
cos U = \(\frac{11^2+8^2-14^2}{2(11)(8)}\)
= \(\frac{121+64-196}{176}\)
= \(\frac{185-196}{176}\)
= \(\frac{-11}{176}\)
Then
∠ U = \(cos^{-1}\) ( \(\frac{-11}{176}\) ) ≈ 93.6° ( to the nearest tenth )
