Triangle Congruence #1

This GeoGebra example dynamically constructs two triangles to visually demonstrate the fundamental conditions for triangle congruence. The core mathematical concept is that congruent triangles have equal corresponding sides and angles, along with common congruence criteria such as SSS, SAS, ASA, etc. Construction details: using the Polygon command to create two triangles poly1 and poly2 with vertices A, B, C and D, E, F respectively; the Angle command marks corresponding angles α and β; by dragging vertices, students can observe how the two triangles remain congruent under changes in side lengths and angles. This is suitable for middle school geometry teaching, helping students understand the definition and criteria of triangle congruence, and can be used for interactive classroom demonstrations or self-directed exploration.