Points on a ring: An interactive walkthrough of a popular math problem
Summary
The post presents an interactive visualization of the classic probability problem: four random points on a circle, and the chance they all lie within some semicircle. It contrasts a wrong fixed-anchor reasoning with a correct, anchor-based approach that shows mutual exclusivity of anchors and derives the general probability N/2^{N-1} for N points, with extensions to smaller arcs and higher dimensions.