I’m just going to explain how I got my answer because it might help you understand for any future problems you have like this!!
So in this case, AEB is a mirrored dilation, or for easier terms, smaller twin, of CED, so if AEB was enlarged to the same size as CED, all the angle sizes would be the same, so we have to find the dilation factor of AEB. The dilation factor is basically just how many times smaller AEB is than CED. To do this, we’re going to take a similar angle measurement from both and divide them. So, angle ABE, and angle EDC would be the same angle, so we’re going to take those measurements, so 35 divided by 18 to get 1.94. That means 1.94 would be our dilation factor. In order to find angle a, we’re going to take it’s matching angle measurement on the opposite figure, which would be angle ECD and divide that by 1.94, so 43/1.94 which would give you around 22. The actual answer was like 22.164, but I would just round to 22!! Your final answer would be A= 22 degrees!! Apologies if this is wrong, I tried my best!!