Question

Find the number that belongs in the green box

round your answer to the nearest tenth​

Answer 1

14.2°

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°