Angelfish are notoriously hard to sex. The only sure way is to wait until breeding and look at their sex organ. However, there are physical traits that can be suggestive of sex. I'd say the top is female (no bump on head, large angle slope to dorsal fin) and the bottom two are males (bumpy heads, right angle between dorsal fin and body).
Had a feeling those were males as they keep pecking at each other trying to find the dominant one .do I take one male out and hope the female goes with the other angel fish,I have got two more a big black one and another yellow but the small yellow is to small I think to sex
Yeah at the moment I'm trying to sell the black one but don't no the name of it and the other yellow one is tiny compared to the rest so thinking he could go instead of the black one as he keeps getting picked on,hence the jug in the water he hides in there