[Mithrandir]

Pointless note: Another way to solve that triangle is to flip the left-most leg of it counterclockwise until it's exactly parallel with the rectangle. It is then plain to see it's half of the rectangle.

[barrkel]

Do you mean rotate the triangle counter-clockwise? The leftmost leg of the triangle is longer than the left edge of the rectangle, so I don't think it will be as plain as you suggest. You'll end up with something like this:

    +--------------------+
    |                  /
    +---------------/--------+
    |            /           |
    |         /              |
    |      /                 |
    |   /                    |
    |/                       |
    +------------------------+

[Mithrandir]

If I was being tested on process, I'd have gotten a 0. Thank you.

[wging]

For what it's worth, here's Lockhart's actual article (warning: pdf) http://www.maa.org/devlin/LockhartsLament.pdf .