Are [a]
An are (a) is a unit of area equal to 100 square meters (m²). It is commonly used in land measurement, especially in some European countries. 1 are = 100 m² = 0.01 hectares. Ares are useful for measuring small plots of land or gardens.
Square Pole
A square pole is another name for a square rod or square perch, a traditional unit of area used in land measurement.
1 pole (rod) = 16.5 feet
1 square pole = 16.5 ft × 16.5 ft = 272.25 square feet ≈ 25.29 square meters
160 square poles = 1 acre
Square poles have historically been used in surveying and describing land parcels.