Explore the fundamental concepts of affine one-dimensional geometry and discover the Triple Quad Formula in this 27-minute video lecture. Delve into the second most important theorem in mathematics, examining how to measure the separation between two points and the relationship between three collinear points. Learn about measuring in affine geometry, the symmetry of distance, and the derivation of the Triple Quad Formula. Engage with an interactive segment where you're encouraged to deduce the formula independently before it's revealed. Follow along as the lecturer provides examples and a proof of this crucial mathematical concept, gaining valuable insights into rational geometry and its foundations.