Answer and Explanation:
Formal regions are the places that present homogeneity, that is, these regions present something balanced and with some among them such as climatic homogeneity, homogeneity of vegetation and soil. This does not mean that they have the same elements, but that the differences are punctual and with similar variations between them.
Functional regions in Pennsylvania are just the opposite of formal regions. This is because the functional regions are those that do not have homogeneity, neither in cultural terms nor in the physical elements of their region. It may seem that in a single region, such as Pennsylvania, this type of region is not prevalent, but it is very common to see this type of region anywhere.
The vernacular regions, are the formal and functional regions within people's perception, for example, an entire city can be a vernacular region, without taking into account its formal and functional locations, however taking into account the perception of the region that people have. For people, a city is a unique region, that is, a vernacular region.
