## Sunday, February 17, 2013

### In Which Lawson Pulls a Number Out of His Ass

I had been written up by the President of the College for use of complex trigonometry in my carpentry class. Let's see what this consisted of. Continuing from yesterday's installment...
----------------------------------------------

Later, during the year, there were a in fact couple of occasions here and there when I think I was able to enrich the class with small doses of trigonometry. I made a point of never using sines or cosines, only tangents, because that’s what carpenters deal with in terms of rise over run. For example, there’s a rule of some sort to the effect that the slope of a staircase is supposed to be between 30 and 37 degrees. How do they convert to this from rise over run, which is the way they cut and measure a stringer? I showed them how to do this on their calculators: it’s the Inverse Tangent function. Complex trig? Call it that if you like, but there’s no other way to do it. And it’s not as though I tested them on this material; I just thought they ought to have a chance to see how its done. My favorite trig episode came when they were working in the shop on compound mitre cuts for hip rafters. I think the slope of the roof was something like 5:12, and in the course of the discussion, I asked if anyone could figure out what was the corresponding angle. Just as the students were reaching for their calculators, there came a calm voice from the back of the class: “Twenty six degrees.”  A stunned silence fell over the room. The student was Lawson, a nice guy and quite an ordinary student. His hands were at his side and he was looking straight ahead. Having some idea what he must have done, I asked him: “What did you do, pull that number out of your ass?” (That’s the kind of teacher I was.) He smiled and said that he remembered seeing that angle dialed in on the mitre saw down in the shop the previous day when they were cutting their rafters. I especially liked that episode because on any given day, you never knew which student would be the smartest one in the class for at least a brief moment. And I like to think that everyone else might have also learned something.

But enough of me apologizing for talking about trigonometry in math class. (!?!) A year later, during my dismissal procedings, I repeatedly pressed my claim that no feedback whatsoever had ever been provided to me regarding deviation from the curriculum. In fact I distinctly (and quite gleefully, based on our written correspondence) emphasized the point that my supervisor, Selwin Peter, was outright lying when he claimed the opposite. So when the College President canvassed all the instructors in the Trades Department to find examples, she had every reason to want to rub my nose in it by giving as many cases as possible, the more egregious the better...if only she could. In fact she came up with exactly three cases, the smokestack being Exhibit A. And as an argument for my dismissal, it is patently absurd.