ASA Triangle Congruence Construction

This GeoGebra example demonstrates the ASA (Angle-Side-Angle) triangle congruence criterion by constructing a triangle from two angles and their included side. The core mathematical concepts covered include triangle congruence, the ASA congruence theorem, angle measurement, segment length, and the role of rigid motions such as rotation in establishing geometric equivalence. The construction uses GeoGebra commands Point, Segment, Angle, Rotate, Ray, and Intersect, generating objects such as points A, B, C, D, E, F; angles α, β, γ, δ, ε, ζ; segments, rays, lines, and text labels to dynamically illustrate how two angles and the included side uniquely determine a triangle. It is suitable for middle school geometry (grades 7–9) and high school review of congruence and similarity, serving as a classroom demonstration, student exploration tool, or visual aid for teaching congruence proofs.