Lines of latitude and longitude intersect at right angles on a ____ projection map. The ___ projection map is useful for planning air routes?

Use MERCATOR. All latitude and longitude lines intersept at right angles. and any other straight line is a line of 'Constant Bearing' , which is suitable for navigation . ; planning air routes.

let us try to apply some trial and error.

google1 "azimuthal equidistant" yields

The azimuthal equidistant projection is an azimuthal map projection. It has the useful properties that all points on the map are at proportionately correct distances from the center point, and that all points on the map are at the correct azimuth (direction) from the center point. A useful application for this type of projection is a polar projection which shows all meridians (lines of longitude) as straight, with distances from the pole represented correctly. The flag of the United Nations contains an example of a polar azimuthal equidistant projection.

google2 "winkel tripel" yields

The Winkel tripel projection (Winkel III), a modified azimuthal map projection of the world, is one of three projections proposed by Oswald Winkel in 1921. The projection is the arithmetic mean of the equirectangular projection and the Aitoff projection:[1] The name Tripel (German for "triple") refers to Winkel's goal of minimizing three kinds of distortion: area, direction, and distance.[

google3 "Robinson" yields

The Robinson projection is a map projection of a world map which shows the entire world at once. It was specifically created in an attempt to find a good compromise to the problem of readily showing the whole globe as a flat image.[1]

The Robinson projection was devised by Arthur H. Robinson in 1963 in response to an appeal from the Rand McNally company, which has used the projection in general purpose world maps since that time. Robinson published details of the projection's construction in 1974. The National Geographic Society (NGS) began using the Robinson projection for general purpose world maps in 1988, replacing the Van der Grinten projection.[2] In 1998 NGS abandoned the Robinson projection in favor of the Winkel tripel projection for that use as it "reduces the distortion of land masses as they near the poles".[3

google4 "mercator" yields

The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator in 1569. It became the standard map projection for nautical purposes because of its ability to represent lines of constant course, known as rhumb lines or loxodromes, as straight segments that conserve the angles with the meridians. While the linear scale is equal in all directions around any point, thus preserving the angles and the shapes of small objects (which makes the projection conformal), the Mercator projection distorts the size of objects as the latitude increases from the Equator to the poles, where the scale becomes infinite. So, for example, Greenland and Antarctica appear much larger relative to land masses near the equator than they actually are.

Mercator

Mercator and azimuthal equidistant