let the vertices on either side of the 0 be A and B
then let the vertex opposite of O be C
First, angle ACB will be equal to 90° as it is the angle that lies on the same arc as the diameter. From there you can find angle y with angle A+ angle B+ Angle C=180°
then you can find the angle complementary to x with the same formula then you can subtract that angle with 90° to get x.
