Distance A map is equidistant when it portrays distances from the center of the projection to any other place on the map. Scale Scale is the relationship between a distance portrayed on a map and the same distance on the Earth. When a map portrays areas over the entire map so that all mapped areas have the same proportional relationship to the areas on the Earth that they represent, the map is an equal-area map. Different map projections result in different spatial relationships between regions. Three Different Map Projections of the United States Albers Equal Area and Lambert Conformal Conic Projections of North America Map projections fall into four general classes.
Cylindrical projections result from projecting a spherical surface onto a cylinder.
When the cylinder upon which the sphere is projected is at right angles to the poles, the cylinder and resulting projection are transverse. When the cylinder is at some other, non-orthogonal, angle with respect to the poles, the cylinder and resulting projection is oblique. When the cone is tangent to the sphere contact is along a small circle. In the secant case, the cone touches the sphere along two lines, one a great circle, the other a small circle. Azimuthal projections result from projecting a spherical surface onto a plane.