Answer:
A formal region is a geographical area that is defined by a set of specific characteristics or features, rather than by political or administrative boundaries. An example of a formal region is the "Bible Belt" in the southern United States, which is defined by the concentration of religious adherence and conservative cultural values rather than by state lines. Formal regions can also be defined by natural features such as climate, vegetation, or topography, such as the "Great Basin" in the western United States which is defined by its hydrographic characteristics, as well as its cultural and economic characteristics.