The first step is always to make an illustration of the problem. My understanding of the problem is shown in the attached picture. To make the problem easier to solve, I assumes that points C, A and D are collinear. Because if it isn't we can't find any relations that can solve the problem.
∠DAB and ∠CAB are supplementary angles. So,
∠CAB = 180 - 110 = 70°
Since a triangle has 180° altogether,
x = ∠ABC = 180 - 70 - 20 = 90°
