Rotating Cuboid with Midpoint Triangle

① This example demonstrates a cuboid rotating in 3D space with a triangle formed by midpoints of its edges or faces, showing dynamic transformations and geometric relationships. ② Core math concepts include solid geometry (cuboid properties), midpoint theorem, triangle construction, rotation transformations, Pythagorean theorem for distance calculations, and complex numbers possibly used for rotation representation. ③ Construction details: GeoGebra commands such as Segment, Point, Cube, Polygon, OrthogonalLine, Intersect, Distance, and Midpoint are used to build the cuboid faces (faceABCD, etc.) and edges (edgeAD, etc.), then midpoints M, points P, Q, and polygon poly1 create the midpoint triangle, with auxiliary line l and point n facilitating rotation. ④ Suitable for high school or early college students learning solid geometry, spatial reasoning, and dynamic geometry construction, as well as for teachers demonstrating rotating solids and cross-sections.