In my private school, we generally have two classes per grade. In Geometry, one class spends one year and the other 1.5 years. I have heard of 1.5 year courses at other school too.
They eliminated Math A and Math B, partly since almost everyone needed 1.5 years (or more) for each, but having courses for slower students that spend 1.5 years or longer to prep for a regents (IA, Geo, or A2T) are still allowed. And, if a student is in a 1.5 year (3 semester) geometry (or IA or A2T), it does count as 1.5 of the 3 required math credits - at least by NYS.