Answer:
Q = 40.6°
Explanation:
Given three sides: 9.6, 8.1, 6.3
Use the cosine rule:
c² = a² + b² - 2ab cos(C)
Insert following variables:
6.3² = 9.6² + 8.1² - 2(9.6)(8.1) cos(Q)
39.69 = 157.77 - 155.52 cos(Q)
cos(Q) = -118.08/-155.52
cos(Q) = 41/54
Q = cos⁻¹(41/54) = 40.6°
