Final answer:
A formal region is defined by common human or physical properties such as language, religion, climate, or landforms.
Step-by-step explanation:
A formal region is defined by common human property, such as the presence of people who share a particular language, religion, nationality, political identity, or culture; or by a common physical property, such as the presence of a particular type of climate, landform, or vegetation.
Regions in geography serve as a fundamental unit of analysis and are characterized by certain definitive features that provide a sense of place or identity. While a formal region could be recognized by governmental or administrative boundaries, it could also be determined by physical characteristics like mountains or cultural traits such as language.
A functional region, on the other hand, is organized around a node or focal point and serves a particular purpose such as a metropolitan area with a city at its center. A perceptual region is based on the subjective feelings and attitudes of people about an area.