Without going too much into the proofs angle ACD is congruent to angle DBA.
If ACD is ~= DBA then
ACD = 54 degrees
Step-by-step explanation:
The figure is a reflection. While orientation isnt preserved in reflections side lengths and angle measures are.
This means that both triangles have the same side length measures and have the same angle measures.
You are given the angle measures of one of the triangles. We also know both triangles are congruent since they both fit perfectly inscribed in the circle.
With this in mind you can prove that all the angles of each triangle are congruent.
Thus
ACD = 54 degrees