What is the purpose of a sectional line in technical drawings?

• A. Indicates a cutting plane and shows the material cut in a sectional view
• B. Marks the scale of the drawing
• C. Identifies hidden features
• D. Defines the overall dimensions of the project

Answer: (A)

Sectional lines indicate where a cut is made to reveal interior features in a sectional view. They mark the cutting plane and show the material that has been removed so the viewer can see inside the object, often with hatch marks to represent the material. This helps convey internal geometry, holes, cavities, and other details that aren’t visible from the exterior.

Other options describe different drawing conventions: scale is indicated separately by a scale annotation, hidden features are shown with hidden lines, and the overall dimensions are given by dimension lines and callsouts, not by where a sectional line is placed.