A land measurement used in the government rectangular survey system (U.S. Public Lands Survey). A township is six (6) miles in length on each side, with a total area of 36 square miles. It contains thirty-six (36)sections, each with an area of 640 acres, for a total area of 23,040 acres. Note that due to the curvature of the earth, a correction of 198 feet must be made every 24 miles. Therefore, many townships actually contain less than 36 square miles due to these corrections.