trig..experts...help! Will give brainly!

Answer:
Step-by-step explanation:
189² = 215² + 123² - 2(215)(123)cos x°
35,721 = 46,225 + 15,129 - 52,890 cos x°
35,721 = 61,354 - 52,890 cos x°
52,890 (cos x° ) = 25,633
cos x° = 25,633 ÷ 52,890 ≈ 0.4846
x° ≈ 61.01°