Explanation: Andrea Del Verocchio was also a painter and so it was easy for him to help his fellow painter in "The delivery of the keys" as is common for people in the same field to give each other ideas of their various projects, especially if they have a good working relationship and admire each others work. This was clear between these two great painters from the Roman Empire as seen in the background figures in the painting which were added by Perugino in this Masterpiece, from the suggestion of his fellow painter Andrea Del Verrocchio. It also also widely believed that Andrea inspired most of the apostle figures in the painting including that of St John. He was known for painting figures with flowing attributes, hence the long flowing hair. It is also believed that Perugino learned a lot from Andrea Del Verrocchio therefore he was, we could say a student of the Andrea.
