geometry help greatly needed. please help if possible.

Answer:
[tex]\huge\boxed{\sf x = 90\°}[/tex]
Step-by-step explanation:
If AB is diameter, the angle opposite to it, when a triangle is inscribed in that semi circle, will be 90 degrees.
Given that:
AB is the diameter.
According to what is given, we come to know that <ACB = x = 90°.
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!