Unit Circle with Trigonometric Lines

① This GeoGebra example dynamically illustrates the unit circle and how the sine, cosine, and other trigonometric values correspond to geometric segments as a point moves around the circle. ② Core mathematical concepts include the unit circle definition, trigonometric lines (sine and cosine segments), angle-radian conversion, and connections to slope, logarithmic functions, and stochastic processes. ③ Construction details: uses Intersect to find circle-line intersections, Circle to define the unit circle, Point for the moving point, Line for auxiliary lines, and Polygon to form a triangle; objects include center A, circle c, moving point B, function f, intersection C, polygon poly1, auxiliary circle c_1, and segments a and b. ④ Suitable for high school and early college students learning trigonometric periodicity, unit circle identities, and dynamic angle-function relationships; also useful for teachers demonstrating interactive geometry.