Be honest: did you actually read [the above geometric proof]? Of course not. Who would want to? The effect of such a production being made over something so simple is to make people doubt their own intuition. Calling into question the obvious by insisting that it be 'rigorously proved'.. Is to say to a student 'Your feelings and ideas are suspect. You need to think and speak our way.
I had a feeling once about Mathematics - that I saw it all. Depth beyond depth was revealed to me - the Byss and Abyss. I saw - as one might see the transit of Venus or even the Lord Mayor's Show - a quantity passing through infinity and changing its sign from plus to minus. I saw exactly why it happened and why the tergiversation was inevitable but it was after dinner and I let it go.
Elodin proved a difficult man to find. He had an office in Hollows, but never seemed to use it. When I visited Ledgers and Lists, I discovered he only taught one class: Unlikely Maths. However, this was less than helpful in tracking him down, as according to the ledger, the time of the class was 'now' and the location was 'everywhere.