Tetrahedral Stacking of Four Spheres

This GeoGebra example demonstrates the geometric structure of four spheres stacked in a tetrahedral arrangement in 3D space. Using Sphere and Tetrahedron commands, it constructs the spheres and their enclosing tetrahedron, visualizing spatial relationships between sphere centers, the faces (faceBCD, faceCDE, etc.) and edges (edgeBC, edgeCD, etc.) of the tetrahedron, and the tangency contacts betwe