🔍 Key Concepts

• Dimension line – shows the distance between two points, usually with arrowheads at both ends and a numerical value. • Leader line – a thin line with an arrow or dot that points from a note or number to the feature it describes. • Cutting plane line vs. phantom line – both can be broken/long-dash styles, but the cutting plane line usually has arrows and labels for the section view, while a phantom line shows alternate positions or adjacent parts.

💭 Think About

• Look at what line C is connected to: Is it indicating a measurement, pointing to a note, or outlining where a section view is taken? • Compare the style of line C (thickness, dash pattern, arrowheads) with other labeled lines in the figure, especially the ones clearly marking a section view. • Ask yourself what new information line C adds to the drawing that the visible edges alone would not show.

✅ Before You Answer

• Verify whether line C has dimension numbers associated with it; if not, it is probably not a dimension line. • Check whether line C has arrows and section labels (like I–I) that would indicate a cutting plane line. • Confirm if line C is simply pointing from a note or label to a feature, which would indicate a leader line.