Answer:
a ≈ 22.184
Step-by-step explanation:
Using the Cosine rule in Δ ABC
a² = b² + c² - 2bc cosA
Here b = 15, c = 12 and A = 110° , then
a² = 15² + 12² - (2 × 15 × 12 × cos110° )
= 225 + 144 - 360 cos110°
= 369 - 360 cos110°
= 492.12725.. ( take the square root of both sides )
a = [tex]\sqrt{x492.12725}[/tex] ≈ 22.184 ( to 3 dec. places )
