What is the primary purpose of contour lines on a map?

• A. To show elevation and terrain shape
• B. To show political boundaries
• C. To show population density
• D. To show road networks

Answer: (A)

Contour lines encode elevation by connecting points that are the same height, which lets you see the shape of the land on a flat map. The spacing between lines shows how steep or gentle the terrain is—tight spacing means a steep slope, wide spacing a gentler slope. Closed loops indicate hills or mountains, and other patterns reveal valleys and ridges. Because of this, contour lines are the primary way a map communicates elevation and terrain form. They don’t depict political boundaries, population density, or roads, which are shown using different map features.