Here are my photos:
Real Circles:
Photo 1: Tel-Aviv sea

Photo 2: Camping-coffee

This is an almost ready black-cooked coffee that we usually make when we're camping. It is very strong coffee and smells wonderful. There are some circles in this photo but the coffee makes the main circle.
Implied circles:
Photo 3: wiggly worm
thinking of this project, I was remembering the worms we collected last fishing trip from our garden and their tendency to cruel into a circular position. Again, I didn't had to ask twice from my son to find me a worm in our garden and took a photo of it. I think that the photo turns out great as the position if my son's hands makes a circular feeling to it.
Photo 4:

Taken at the Haifa zoo this 3 monkeys create 3 implied circles in the photo.
In the textbook I found 2 examples for implied circles:
- "A loving couple" by Paul Martin, circle created by the shadows and footprints on the beach.
- "Ola-Noatak" by Edward Curtis. I have to say that I'm not quite sure it's an implied circle and not a real one but the circle creates from the face and the fur around it.