A Christmas Proof

(Click on the cartoon to see the entire image.) (C)Copyright 2008, C. Burke. All rights reserved.


And, really, what more "proof" do you need?
Cue Josh Groban singing, "Believe"



I wrote this proof on the blackboard my first year teaching in an 8th grade honors math class in the last five minutes of class on the day before Christmas break.
Strangely, now that I teach in high school, I haven't been able to use it as I'm never at the right point in the curriculum for them to follow the "logic".