The Bride's Chair - Futility Closet

The Bride's Chair - Futility Closet

This is Euclid’s proof of the Pythagorean theorem — Schopenhauer called it a “brilliant piece of perversity” for its needless complexity: Erect a square on each leg of a right triangle. From the triangle’s right angle, A, draw a line parallel to BD and CE. This will intersect BC and DE perpendicularly at K and L. Draw segments CF and AD, forming triangles BCF and BDA. Because angles CAB and BAG are both right angles, C, A, and G are collinear. …