Acre (ac)
The acre, or ac, is a unit of area used in the imperial and US systems. It originated in medieval England and referred to the land a team of oxen could plow in a day. Today, one acre is 4,840 square yards or 4,046.856 square meters. Acres are still used in the US, Canada, and the UK for real estate, land sales, and farms. While the metric system is more common worldwide, the acre is still used because it is part of tradition and is easier to use in daily life.
Square Foot (ft²)
The square foot (ft²) is a standard unit of area in both the imperial and US customary measurement systems. Defined as the area of a square with each side measuring one foot, one square foot equals 144 square inches or roughly 0.0929 square meters. Its origins date back to the Middle Ages, and it eventually became a fixed standard. Today, the square foot remains a popular unit in the United States, Canada, and the United Kingdom, especially for describing the size of residential and commercial spaces. Although metric measurements are more widely adopted worldwide, the square foot continues to be important in real estate and construction practices within these countries.