Monday.
It was already a good ten minutes past the final bell.
"Based on this moving endpoint, we can use the method of assumption to place it at a point you find most appropriate, and then work backward to verify whether it causes the line segment to be perpendicular..."
To Sakiko Toyokawa, the blackboard filled with tetrahedral analytical diagrams and proofs looked rather foolish.
The method of directly establishing a coordinate system that Miki Kashiwagi had taught her last time was quite simple. In Miki Kashiwagi's own words:
"Although it's basically only useful in some special situations, those are the only kinds of situations you're ever going to run into right now, Sakiko."
"Though it's a bit troublesome to write down, its advantage is that it's simple. Look, we solved the problem that was bothering you while eating dinner, without even needing to pull out a piece of scratch paper."
She really lived up to being a Doctor. Still, she needed to take her notes properly; the teacher checked them from time to time.
After diligently jotting down a summary of what was on the board, the bespectacled young teacher tapped the blackboard.
"Sorry for keeping you all past the bell for so long. As compensation, I'll assign a bit less homework today. Class is dismissed."
Chapter 69