FYI, since 285 is a loop and 75 runs all the way through Atlanta, there are two 285/75 interchanges. While I think you're correct in your selection, here's the other one for completeness: https://www.google.com/maps/place/33°37'55.6%22N+84°24'02.8%....
This is of practical importance. There are two 285/85 interchanges as well and I broke down at one of them once, and the tow truck thought I was at the other one.
That's sort of true, but "loop" just means that both ends are at interstates. See for example I-675 south of Atlanta, which runs from I-285 to I-75 in roughly a straight line.
