Definition: A square foot (symbol: sq ft or ft²) is a unit of area in the imperial and US customary systems. It represents the area of a square with sides measuring one foot in length. One square foot equals 144 square inches or about 0.0929 square meters.

History/origin: The square foot has been used historically in English-speaking countries as a standard unit for measuring smaller areas, particularly in construction, real estate, and interior design. Its use dates back to the establishment of the imperial measurement system.

Current use: Square feet are extensively used in the United States, Canada, and the UK for measuring floor space in buildings, homes, offices, and land parcels. It remains a fundamental unit for property descriptions, architectural plans, and interior space calculations.

Definition: An acre is a unit of area commonly used in the imperial and US customary systems. It is defined as exactly 43,560 square feet or about 4,047 square meters. Acres are primarily used to measure large plots of land, especially in agriculture and real estate.

History/origin: The acre originated in medieval England as a measure of land that could be plowed by one man with a team of oxen in one day. Its size was standardized over time to the current definition. The acre remains a common land measurement unit in many English-speaking countries.

Current use: Acres are widely used today in the United States, the United Kingdom, and other countries that follow the imperial measurement system. It is frequently used in agriculture, land planning, and real estate to describe the size of plots, farms, and properties.