Point and Geometric Relationship Demonstration

This example demonstrates the construction of geometric figures using points A, B, C, D and illustrates their connections with mathematical concepts such as the cosine function, straight lines, calculus (upper and lower sum or Riemann sum), and orthocenter. Core concepts include the cosine rule, straight line equations, Riemann sums in calculus, and the orthocenter of a triangle. It uses GeoGebra commands for point objects to create points A, B, C, D. Suitable for high school and above students learning analytical geometry, trigonometry, and introductory calculus.