I've snuck back from vacation for just a day, and wanted to get you this link to a wonderful poem by Philip Levine (brief bio).
I could only find this in audio, but I've transcribed the first half to the best of my ability.
Messieur Degas Teaches Art and Science at Durfy Intermediate School, Detroit 1942
by Philip Levine
He made a line on the blackboard
One bold stroke from right to left diagonally downward
And stood back to ask --
Looking as always at no one in particular --
"What have I done?"
From the back of the room Freddy shouted,
"You've broken a piece of chalk!"
Messieur Degas did not smile.
"What have I done?" he repeated.
The most intellectual students
Looked down to study their desks,
Except for Gertrude Bimler,
Who raised her hand before she spoke:
"Messieur Degas, you have created
The hypotenuse of an isosceles triangle."
Everyone knew that Gertrude could not be incorrect.
Go here to hear: Messieur Degas Teaches Art and Science at Durfy Intermediate School, Detroit 1942