Not a photograph, but one of my favorites! High and Low - M.C. Escher
"To have peace with this peculiar life; to accept what we do not understand; to wait calmly for what awaits us, you have to be wiser than I am."
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The Mathematical Art Of M.C. Escher video...you can pause video and explain what has happened or what is to come if it is on a level higher than your students.
Eye drawing by Unknown in the style of Maurits Cornelis Escher (the extended note on post was interesting re the style differences between Escher & the actual artist)
Maurits C. Escher, Eye, 1946
Full Size Image #142303 - Sharenator.com
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How to make Tessellation Art with the kids -- Great links, including a game to teach about tessellation