Which projection uses the property that the parallels are straight lines and the meridians are curved when the plane of projection is tangent at the equator?

• A. Azimuthal equidistant
• B. Orthomorphic
• C. Gnomonic
• D. Polyconic

Answer: (A)

This arrangement is the polyconic projection. It’s constructed so that each parallel (latitude line) is drawn as a straight line on the map, while the meridians (longitudes) appear as curved lines. The plane of projection is taken to be tangent to the globe at the equator, and each parallel is produced by its own cone tangent to the sphere. Because the projection treats each latitude with a separate cone, the parallels map to straight lines, but the meridians do not align into straight lines across all latitudes, so they curve. This combination—parallels as straight lines and meridians as curved lines with the projection plane tangent at the equator—fits the polyconic construction.