Sketch a Day, Day 191 June 6, 2012September 26, 2012 | xeyeti I actually used this explanation in class today, but while I was talking to a student, not my wife. Though it would not be unusual for me to do something like this to her. Share this: Share on Tumblr (Opens in new window) Tumblr Share on X (Opens in new window) X Share on Facebook (Opens in new window) Facebook Like Loading... Related