Square Mile (mi²)
The square mile, or mi², is the area of a square one mile on each side, or 640 acres. Its history dates back to the mile, which originated in Roman times. The square mile became a set measurement in England. It is still widely used in the US and the UK for large areas, such as cities, counties, and parks. Most countries use square kilometers, but in English-speaking regions, the square mile remains common, especially in historical and legal contexts.
Square Yard (yd²)
The square yard, or yd², is an area unit from the imperial system. It is the area of a square with one-yard sides and equals 9 square feet or 0.836127 square meters. Used first in England, the square yard was set as a standard in the 1900s. It is still used in the US and UK, particularly for real estate, carpets, fabrics, and sports fields. While most of the world now uses square meters, the square yard is still recognized and used in certain professions.