Have you ever saw the photo of Pythagoras?

This was a question asked on a lecture today - by the professor. After not getting an answer, he concluded that we didn't see the photo, so he told us he will draw it. I thought about photographing it, but my cell phone camera is not very good. The drawing you see below is my recreation of his drawing:



I am starting to think that this particular professor has a special love to Pythagoras theorem.. Not so long ago he told the class a story about a graduate student, who was asked on a final test for M.S. what do you know about Pythagoras theorem (in Hebrew theorem and trial is the same word), and he answered I think the jury decided he is not guilty...