What is parametric modeling in CAD, and why is it advantageous for design changes?

• A. A model driven by parameters and dimensions; changes propagate automatically to dependent features, saving time.
• B. A model that uses fixed dimensions; changes require manual updates.
• C. A model that uses random values for dimensions; changes are unpredictable.
• D. A model that ignores dependencies; changes affect only the selected feature.

Answer: (A)

Parametric modeling in CAD defines geometry using parameters and relationships between features. When you adjust a parameter, all dependent features recalculate automatically, keeping the intended relationships intact. This makes design changes swift and reliable: you can tweak a single dimension and see the entire part update consistently, which speeds iteration, preserves design intent, and reduces manual edits and errors. If dimensions were fixed, changes would require manual updates to each feature; using arbitrary or random values would yield unpredictable results; and ignoring dependencies would break the model’s coherence and make revisions cumbersome.