Circle Orientation and Dynamic Geometry

① This example demonstrates the orientation of a point moving along a circle (clockwise or counterclockwise) and related geometric elements such as tangents, radii, and intersections, helping learners understand the concept of circle orientation. ② Core mathematical concepts include parametric equations of a circle, vector direction, point trajectories, and the Pythagorean theorem applied to circles and right triangles, along with geometric transformations like dilation and intersection. ③ Construction highlights: using GeoGebra commands such as If, CurveCartesian, Vector, Point, and Segment, the construction builds a circle, lines, intersection points, text labels, and a play button, with sliders controlling speed and direction for dynamic animation. ④ Suitable for middle or high school geometry and analytic geometry classes, this example serves as an interactive teaching tool for circle orientation, parametric equations, and dynamic geometric constructions, and can be a reference for teachers creating interactive lessons.