What type of line is indicated by an arrow labeled A in a technical drawing?

In technical drawings, an arrow labeled A typically indicates a Hidden Line. This type of line represents edges that are not visible from the current viewpoint of the drawing, such as interior edges or contours that would be obscured by other objects. Hidden Lines are usually depicted as short dashed lines, which differentiate them from lines that define visible edges or surfaces.

Understanding the purpose of Hidden Lines is essential in the context of technical drawings, as they provide clarity regarding the structure and components of a design that are not immediately apparent. This helps engineers, architects, and designers convey comprehensive information in their blueprints, supporting accurate interpretation and construction of the item being designed.