In US Land surveys, townships are about 36 square miles. Each square mile is called a section. If you look at section boundary plats, you will find that the southern boundary is wider than the northern boundary. This is because corrections have to be made for the convergence of the meridians.
If the earth were flat, why aren't these sections perfectly square?
US Public Lands System
Section (United States land surveying) - Wikipedia
If the earth were flat, why aren't these sections perfectly square?
US Public Lands System
Section (United States land surveying) - Wikipedia