Which of the following is true about land descriptions?

The statement regarding a 1/2 mile square being 160 acres is accurate because there are 640 acres in a full mile square (which is one section, according to the Public Land Survey System). When you take a half mile in both dimensions, you are effectively taking half of the area of the full mile square. Since an acre is defined as 43,560 square feet, a square that is 1/2 mile by 1/2 mile equals 2,640 feet by 2,640 feet, which results in 160 acres.

In terms of the other options, an acre is not defined as 640 feet square; an acre is a unit of area equivalent to 43,560 square feet. A township is not the same as a tier; townships are square blocks of land that are 6 miles on each side and are made up of 36 sections, while tiers refer specifically to rows of townships running north and south. Lastly, all sections do not contain 640 acres; rather, each section is one square mile, translating to 640 acres, but there are smaller subdivisions of the section that can also exist, leading to different acre measurements in various contexts.

Therefore, the correct answer stands