Farm I grew up on.... we have some fields with less slope than what you show, and some fields with more slope than what you show.  As a rule, where we had steeper slopes, we had shorter slopes.  

Where I live and work now, the limestone farms generally have less slope than what you show, but the farms with shale soils can be as steep or steeper than what you show.  Can be, but not always.

For the record, I live in southcentral PA.

edit: my impression is that terraces tended to be popular in the 1970's into the 1980's.  At least around here.  I just don't see terraces being installed anymore.  I have seen terraces taken out.  My impression of talking with NRCS people is that terraces are costly to install, and encouraging No-till and cover crops is way more cost-effective, and just as effective in reducing soil loss.  At least with the soils and climate conditions we have here in PA.