Reflections on the Coordinate Plane by heidi langius

This GeoGebra example demonstrates the coordinate changes of a polygon under four common reflections (axial symmetries) on the Cartesian coordinate plane, helping users generalize specific mapping rules. Core mathematical concepts include geometric transformations, reflections, preimage and image mapping, and coordinate geometry formulas for symmetry across axes like the x-axis, y-axis, y=x, and y=-x. The construction utilizes key GeoGebra commands such as Polygon to define the preimage, Line to establish reflection axes, Mirror to generate the reflected image, and Intersect for precise vertex alignment. Interactive buttons and dynamic text fields facilitate hands-on exploration of coordinate mappings. It is highly suitable for high school or introductory college students studying coordinate geometry, geometric transformations, and algebraic mappings.