Correlation as a Geometric Mean
Drag points A, B, C, D, and E. The points A', B', C', D', and E' will move in response (these points are of the form (y,x) ). The correlation coefficient is the geometric mean of the slopes of the respective LSRLs.
Miura Ori Crease Pattern
Equilateral Triangle Polynomial Test
Incircle or Inscribed Circle