Amidst the pressure that is mounting as the FCAT is looming, I’ve had absolutely NO time to think about blogging. This little tidbit, however, was too good to file away in my memory box in hopes that it would be written about later…
In September, which seems like years ago at this point, I very speedily taught a unit on Reasoning & Proof to my Geometry classes. (Many of you may remember this as the era that included the infamous sex talk with my 7th period. – “Ms. Nolte, what is lube?” Oh, joy.) One of the things we learned was how to write the converse of a conditional statement.
Here’s a quick lesson, only because it makes the story better: A conditional statement is better known as an if-then statement. Ex. IF it is cloudy, THEN it will rain. The converse of a conditional statement is essentially the same statement, reversed. So, IF it will rain, THEN it is cloudy.
Fast-forward to today, as we’re covering theorems about rectangles.
First theorem: If a rectangle is a parallelogram, then its diagonals are congruent. They marinated on that for a little bit, and we moved on to the next one.
If the diagonals are congruent, then the parallelogram is a rectangle. I let them think that over for a few minutes, and then I got ready to start an example.
And then, the kicker. One of my students says, “Wait a minute, isn’t that like, that thing we learned? What’s it called? The con- converse?”
I TAUGHT THEM SOMETHING. (At least one of them.)