Mercator projection produces a conformal map. Which of the following describes that property?

• A. Conformal
• B. Equal-area
• C. Equidistant
• D. Compromise

Answer: (C)

Conformality means preserving angles at small scales. The Mercator projection is conformal because the scale is the same in all directions at a given latitude, so tiny shapes maintain their angles locally even though their overall size changes with latitude. This angle-preserving property is why navigational courses appear as straight lines on the map. The trade-off is that areas aren’t preserved—the scale grows with latitude (roughly 1 over cosine of latitude), causing polar regions to be greatly exaggerated. Distances aren’t preserved either, since the map stretches more and more as you move away from the equator. Because it prioritizes angle preservation over area or true distances, it is not an equal-area or an equidistant projection, nor is it a compromise projection.