No one can for sure as the only real way is to check their vent underneath or if they lay eggs.. and even then you need a good eye and to know what you are looking for...
However, I have seen an awful lot of Angels and they will always fascinate me, especially behaviours.
My educated guess is that they are both male, though if i was to have a doubt and you had eggs, i would assume the one on the right is the questionable one but thats purely because they are such tiny photos.
Good luck