Final answer:
The cartographer must choose a map projection based on the map's purpose, which influences how size, shape, distance, area, or direction are represented.
Step-by-step explanation:
Because map projections can distort one or more of the properties of size, shape, distance, area, or direction, the cartographer must choose the projection to use based on the purpose of the map. Different map projections serve different purposes; for example, the Mercator projection is convenient for navigation because it preserves angles and directions but distorts the size of landmasses at high latitudes. This is why on a Mercator projection map, Greenland looks as large as Africa when in fact Africa is much larger. Accurate representation of these properties depends on the chosen projection and can influence how we perceive spatial relationships on a map. Cartographers must also include other elements such as a scale that correlates distances on the map with actual distances on Earth, often in both kilometers and miles, a visual scale bar, and an arrow indicating north as well as latitude and longitude lines if possible. Symbols, including colors, lines, and icons, should be explained in a legend to ensure clear communication of the necessary information.