Subject: When land area measurements are given, do they include topography?

As we know, a line is the shortest distance between two points and the sum of 
the lengths of two sides of a triangle is always greater than the length of the 
third.  So, when land area measurements are given (in square miles, acres, 
hectares, etc.)do they include the "extra" land created by hilly or mountainous 
terrain or not?  In other words, does the the same-sized parcel of the earth's 
surface in the Rocky Mountains contain the same acreage, etc. as a parcel in 
Florida, for instance?

Re: When land area measurements are given, do they include topography?