Similar Triangles Activity

① This interactive GeoGebra activity demonstrates the concept of similar triangles, showing how corresponding angles are equal and corresponding sides are proportional. ② Core mathematical concepts include similarity criteria (AA, SAS, SSS), scale factor, corresponding angles and sides, and the triangle angle sum theorem. ③ Construction details: Using GeoGebra commands such as Line, Segment, Point, Intersect, and Angle, the activity constructs triangle ABC with auxiliary lines, points D and E, and segments l, m, n to form similar triangles. Angles α, β, γ, δ, ε and angles BAC, ACB are labeled to highlight equal corresponding angles, while segments a, b, c and auxiliary lines p, q, r support the construction. ④ Suitable for middle school geometry lessons or self-study, this activity helps students explore similarity conditions and visualize how triangles scale while preserving shape.