You can find ∠ACB using the law of cosines:
[tex]cos \angle ACB= \cfrac{AC^2+BC^2-AB^2}{2*AC*BC}= \cfrac{220^2+200^2-160^2}{2*220*200}= \\\\ =\cfrac{48400+40000-25600}{88000}= \cfrac{62800}{88000}= 0.7136 \ \ \to \ m\angle ACB=44.47^o[/tex]
x = 180° - m∠ACB = 180 - 44.47 = 135.53°