Ok thanksYes, or re-home it if that is possible. I was assuming you had the angelfish so it was staying. Angelfish is a shoaling species but a group of five (minimum) needs a much larger space, and even then adding new angelfish to a lone angelfish does not always work out.
While typing, you';ve posted more (and Retired Viking too)...a lone angelfish is contrary to the expectations of the fish, and that is something I never recommend. However, sometimes we are left with a situation that is not the best and we have to somehow manage it. I cannot imagine a mature angelfish in my 29g tank but it may be the kinder option available.