Central and Axial Symmetry: Polygon and Its Mirror Images

①This example demonstrates two fundamental geometric transformations—central symmetry (about point D) and axial symmetry (about line d)—by showing a polygon and its mirrored copies. ②Core mathematical concepts include symmetry transformations, reflection, corresponding points and figures, and the properties of centers and axes of symmetry. ③Construction highlights: using GeoGebra's Polygon command to create the original polygon poly1, then applying the Mirror command about point D and line d to generate mirrored polygons poly1' and poly1'', while also mirroring sides, circles, and other objects, preserving the dynamic relationship between originals and images. ④Suitable for middle and high school geometry lessons, this interactive applet helps students visualize symmetry, explore properties such as corresponding points being equidistant from the center or perpendicular bisectors of the axis, and understand the invariance of shapes under reflection.