What terms describe the basic geometry from which models are built?

The term that best describes the basic geometry from which models are built is "Geometric Entities." In the context of CAD software such as Autodesk Inventor, geometric entities refer to the fundamental building blocks of models, which include points, lines, arcs, circles, and other shapes that define the geometry of a design. These entities serve as the foundation for creating more complex features and models through operations like extruding, revolving, and lofting.

Understanding geometric entities is crucial for mastering the modeling process, as they form the necessary structure to develop parts and assemblies in a CAD environment. The knowledge of these entities allows users to manipulate and create intricate designs effectively.

Other terms like geometric shapes, figures, and aspects do not encompass the full breadth of fundamental geometry used in 3D modeling as comprehensively as geometric entities do. Shapes and figures may refer more to the visual or conceptual representation of geometry rather than its functional aspects in the context of CAD software. Aspects also tend to describe characteristics or properties rather than the essential building blocks required for creating designs.