Polar Coordinates Applet: Points, Lines, and Angles

① This GeoGebra applet dynamically illustrates the relationship between points, lines, and angles in a polar coordinate system, making the conversion between polar and Cartesian coordinates visually intuitive. ② Core mathematical concepts include polar coordinates (r, θ), orthogonal lines, intersections, segments, angle measurement, and coordinate geometry construction. ③ Construction details: uses OrthogonalLine to create perpendicular lines, Intersect to find intersection points, Segment to connect points, Point to define key locations, and Angle to mark angles; objects include points A, B, C, D, lines f, b, c, segment d, angle α, variables r, a, xa, ya, and text objects text1 and text2, with sliders or inputs controlling the radial distance and polar angle. ④ Suitable for high school or early college students learning analytic geometry and polar coordinates, as a visual aid for introducing limits and integrals in calculus, or as a classroom demonstration tool for teachers.