What type of line represents an edge that is behind a face in a technical drawing?

• A. Visible Line
• B. Section Line
• C. Hidden Line
• D. Construction Line

Answer: (C)

In technical drawing, the type of line that represents an edge behind a face is known as a hidden line. This line is typically depicted as a dashed or dotted line, indicating that the edge or surface is not directly visible from the current viewpoint of the drawing. Hidden lines are crucial for providing a complete representation of the object, showing features that are obscured by other parts.

The use of hidden lines allows the viewer to understand the depth and complexity of the object’s design, which is essential in engineering and architectural contexts where precision is vital. By illustrating parts of the object that cannot be seen from the outside, hidden lines help convey the full geometry and functionality of the design, aiding in clear communication among designers, manufacturers, and builders.

In contrast, visible lines represent edges that are clearly seen, section lines indicate where a section cut has been made, and construction lines serve as guidelines for drawing and are typically not part of the final presentation of the drawing.