Law of Cosines Proof by Sook Campanelli

This example dynamically demonstrates the proof of the Law of Cosines, showing that the square of any side of a triangle equals the sum of the squares of the other two sides minus twice their product times the cosine of the included angle. It involves core concepts like the Law of Cosines, triangle geometry, vectors, and coordinate geometry. Construction highlights include using GeoGebra commands such as Polygon, Angle, OrthogonalLine, Intersect, Segment, Slider, and Locus to build the triangle and auxiliary lines, and to visualize dynamic changes. Suitable for high school students and teachers to understand the proof process and geometric significance.