Answer:
14.2°
Step-by-step explanation:
We solve this using the Cosine rule formula
From the question we have
Side a = 5
Side b = 11
Side c = ?
We are given Angle C = 120°
Hence,
c² = a² + b²− 2ab cos(C)
Hence,
c² = 5² + 11² - 2(5 × 11) × cos (120°)
c =√[ 5² + 11² - 110 × cos (120°)]
c = 14.18 °
Approximately to the nearest tenth
c = 14.2°
