Which term describes non-visible edges and surfaces in a view?

Which term describes non-visible edges and surfaces in a view?

• A. Hidden lines
• B. Center lines
• C. Section lines
• D. Extension lines

Answer: (A)

Hidden lines describe edges and surfaces that aren’t visible in a given view. In drafting, these features are shown with short dashes to indicate what lies behind or inside the object—like a pipe behind a wall or a recessed detail inside a cabinet—so readers understand concealed details without needing a separate sectional view. Other line types serve different purposes: center lines mark symmetry or axes, section lines show where a cross-section is taken, and extension lines are used to extend dimensions beyond the object. Using hidden lines helps you interpret what’s hidden from view when inspecting building plans.

Hidden lines describe edges and surfaces that aren’t visible in a given view. In drafting, these features are shown with short dashes to indicate what lies behind or inside the object—like a pipe behind a wall or a recessed detail inside a cabinet—so readers understand concealed details without needing a separate sectional view. Other line types serve different purposes: center lines mark symmetry or axes, section lines show where a cross-section is taken, and extension lines are used to extend dimensions beyond the object. Using hidden lines helps you interpret what’s hidden from view when inspecting building plans.