What is defined as restrictions applied to geometric entities in a model?

The correct answer is geometric constraint, as it specifically refers to the limitations or rules applied to geometric entities within a model that dictate their size, position, and relationship to other entities. Constraints control how geometric elements interact with one another, ensuring that they behave in a predetermined way when modifications are made. For instance, a dimension may constrain the length of a line, or a geometric relation may ensure that lines remain parallel.

In the context of modeling, geometric constraints are crucial for maintaining design intent. They help designers create more robust models that respond predictably to changes. For example, if a horizontal constraint is applied to a line, it will remain horizontally aligned even as other parts of the model are adjusted.

Other options like geometric relation, geometric feature, and geometric property describe aspects of geometric modeling but do not encapsulate the idea of applying restrictions to entities. A geometric relation refers to how entities are associated with each other, a geometric feature describes specific elements like holes or fillets in a model, and a geometric property pertains to characteristics such as size or color. While these terms are relevant to geometric modeling, they do not convey the concept of constraints that control behavior and relationships among geometric entities.