Cross Section of a Sphere: Dynamic Geometry Exploration

① This GeoGebra example dynamically demonstrates the cross-section of a sphere by a plane, showing that the intersection is a circle (or a point) and visualizing its geometric properties. ② Core mathematical concepts include solid geometry (sphere, plane section), circles, isosceles triangles (relating section radius to sphere center distance), similar triangles, and rational number ratios. ③ Construction highlights: using GeoGebra commands such as Translate, Rotate, Sphere, Cone, IntersectPath, and Segment; key objects include sphere sp, section circle co, auxiliary points G, AA, GG, and text labels text1/text2/text3; sliders (rr, tt, ud) control parameters for dynamic interaction. ④ Suitable for high school or early college students learning solid geometry, and for teachers as an interactive classroom demonstration to enhance spatial reasoning about sphere sections.