Movable Triangle Under Axial and Central Symmetry

This GeoGebra example demonstrates a movable triangle undergoing axial (reflection) and central (point) symmetry transformations in the plane. Core mathematical concepts include plane geometric transformations, reflection across a line, point symmetry about a center, polygon vertex mapping, and congruence of transformed figures. The construction uses the Polygon command to create the original triangle poly1, the Mirror command to generate symmetric images such as poly1', the Segment command to draw symmetry axes or connectors, and LaTeX text objects text1 and text2 for annotations. Key objects include vertices A, B, C, D and their reflected images B', C', D', along with derived polygons and segments. It is suitable for middle school geometry instruction on transformations and for high school review of symmetry properties, supporting interactive classroom demonstrations and student exploration.