Hoping that the Angle of B is 88 ;
1. Using the Rule, sum of interior angles of a Triangle is Equal to 180:
180 - 88 = 92
2. Using the Rule that Angle A = Angle C ( since its an Isosceles triangle ) :
92 / 2 = 46
Therefore A=46 & C=46
3. Using the Rule, Angle of a Straight line is 180:
Angle of C = 46
X = 180 - 46
X = 134
Hence Solved ✌
I Hope it helps!