Composition of 3 Reflections - General Position

① This example demonstrates the effect of applying three successive reflections (mirror images) about three different lines in general position to a planar figure, showing the intermediate and final transformed shapes. ② The core mathematical concepts are reflection transformations and their composition, including properties of isometries (distance-preserving transformations), and the result that the composition of three reflections is equivalent to a rotation or a translation depending on whether the three mirror lines are concurrent or parallel. ③ Construction details: Based on the construction summary, the GeoGebra commands used include Line, Intersect, Rotate, Point, Mirror, and Polygon. The construction creates three mirror lines a, b, c, an initial polygon, and successive reflected polygons (e.g., N', O', P', etc.), with buttons (button1, button2) to control the interactive steps. ④ This is suitable for high school or early college geometry courses to understand composition of reflections, classification of isometries, and interactive construction in dynamic geometry software.