I was the exact same way with angles on CDP...I got 21s on the first 3 tests, and got like 14 or 15 out of 15 on every section except angles. It's crazy- whenever I reviewed my answers, the angle degree measurements were all within like 3 degrees of each other! I tried a new method yesterday and took two full-length PAT tests and got a 22 and a 23.

What I did was look at the answer choices first...generally, of the 4 multiple choice options, the smallest ranked angle will be one of two choices (say your 4 choices are 4123, 4132, 1432, 1243...the smallest angle is thus going to be angle 4 or 1). Compare just those two angles and decide which is smaller- now you've already increased your chances of getting the right answer to 50%. Do the same for the largest angles...ie) for the 4 options I listed, the largest angle has to be 3 or 2. This method doesn't work every single question, but it definitely helps narrow it down so that you are only comparing 2 angles at once instead of 4. I went from 8/15 to 14/15 on angles with this....its worth a shot!