Interactive Unit Circle in Radians with a Slider

This example visualizes the unit circle (radius 1) with a slider that continuously changes the angle in radians, showing how the corresponding point on the circle moves and how related geometric constructions evolve. It centers on key concepts: the unit circle, radian measure, and the coordinate interpretation of cosine and sine as the x- and y-coordinates of the rotating point. The construction is built using core GeoGebra commands such as Intersect, Circle, Point, Segment, and OrthogonalLine to create the circle, key points on the circumference, and auxiliary segments/orthogonal lines that link the angle parameter to measurable geometric relationships. The scene includes intersection-generated objects and labeled elements (text objects) to make the evolving configuration easy to read. Suitable for secondary to early university levels, especially for learning trigonometry, radian-angle interpretation, and interactive geometry demonstrations.