Triangle Congruence: Angle-Side-Angle (ASA) Exploration

① This interactive GeoGebra activity demonstrates the Angle-Side-Angle (ASA) congruence criterion for triangles: if two angles and the included side of one triangle are congruent to the corresponding parts of another triangle, the triangles are congruent. ② The core mathematical concept is triangle congruence, involving angles, sides, rotation, and intersection of lines. ③ Construction details: using GeoGebra commands such as Point, Segment, Rotate, Angle, Line, and Intersect, the activity constructs triangle ABC and its rotated image A'B'C', with labeled angles α, β, γ and sides a, b, c, d, e, f, plus auxiliary objects like b_1 and showc, to dynamically illustrate the ASA condition. ④ Suitable for middle school geometry lessons or self-study, this resource helps students visualize and verify the ASA congruence theorem, and can be used by teachers for classroom demonstrations or by learners for independent exploration.