Demonstrating Why Negative Numbers Multiply to Positive

This example visually demonstrates why the product of two negative numbers is positive using dynamic geometry. It involves core concepts like multiplication rules for negative numbers, vectors, and parallelogram area. GeoGebra commands used include Point, Segment, Line, Intersect with objects like points A, B, C, vectors vec, a, b, and others. Suitable for middle school students and above to understand the sign rule in multiplication or as a teaching tool for mathematical visualization.