Spirolateral with 90° Turns Construction

This example demonstrates the construction of a spirolateral, a polygonal spiral formed by connecting equal-length segments with a fixed 90° turn angle, where the sequence of segment lengths can be varied to produce diverse spiral patterns. Core mathematical concepts include sequences and series, modular arithmetic (Mod), vectors, and polyline construction, along with the role of the 90° angle in determining the path's direction. Construction highlights: using GeoGebra's Textfield (InputBox1) for parameter input, Sequence to generate the length list, Mod to compute turn directions, Vector for unit direction vectors, Intersect for finding vertices, Length for measuring segments, Union to merge paths, PolyLine to draw the polyline, and buttons (button1/2/3) to control iteration steps or reset. Suitable for high school to early college students exploring number-driven geometric patterns, and useful for introductory programming-based geometric construction.