Which projection maps from a globe onto a piece of paper that touches the globe at a single point?

• A. Gnomonic Projection (Single Point)
• B. Mercator Projection (Cylinder)
• C. Conic Projection (Cone)
• D. Longitude (Vertical)

Answer: (A)

The idea being tested is a projection that uses a plane touching the globe at just one point. That setup is the gnomonic projection. How it works: imagine a flat sheet that is tangent to the globe at a single location. From the center of the globe, draw lines through points on the surface until they meet that tangent plane. Those intersection points on the plane are the projected locations. Because the plane only touches at one spot, everything on the map is built from that single contact point, and a notable property is that great circles on the globe appear as straight lines on the map, which is why navigators like this projection for plotting shortest routes. Distortion grows quickly as you move away from the contact point, so shapes and areas aren’t preserved there.

The other options involve different ways of attaching a sheet to the globe. A cylinder (like a Mercator map) wraps around in a way that touches along a line, not at a single point. A cone (a conic projection) meets the globe along a circle of latitude, not a single point. And labeling longitude as a projection doesn’t describe a true projection method.