9514 1404 393
Answer:
117.9°
Step-by-step explanation:
Solving the Law of Cosines equation for C, we get ...
C = arccos((a² +b² -c²)/(2ab))
Filling in the values from the figure, we find the angle X to be ...
X = arccos((y² +z² -x²)/(2yz)) = arccos((55² +50² -90²)/(2·55·50))
X = arccos(-2575/5500) ≈ 117.9°
