Just to remind you, my method usesextremely simple geometryto create pi, in fact, it only uses the pythagorean theorum Just for your information, I'm currently in "freshman geometry" in high-school, I haven't reached calculus

(I must have fooled you )

The way I set up the problem, $\displaystyle \Delta y$ is always negative. However, since the pythagorean theorum uses $\displaystyle \Delta y^2$ I decided it didn't matterAnd one thing I spoted is that you set $\displaystyle \Delta y = \sqrt{\Delta y^2}$, that's equal to $\displaystyle |\Delta y|$ for real numbers $\displaystyle \Delta y$.