Sphere Intersections: Visualizing Elliptical Cross-Sections in 3D

① This example demonstrates the intersection of two spheres in 3D space, showing the resulting elliptical curve where the surfaces meet. ② Core math concepts include sphere equations, solid geometry, conic sections (ellipse), and set-theoretic intersection visualized geometrically. ③ Construction uses GeoGebra commands: Point to define centers A and B, Sphere to create spheres a and b, PointIn to place points on surfaces, IntersectConic and Intersect to compute the intersection ellipse and points, yielding objects C, D, E, etc. ④ Suitable for high school or early college students studying solid geometry, analytic geometry, and set theory, as well as teachers demonstrating 3D intersections interactively.