Square Decimeter [dm²]
A square decimeter (dm²) is a unit of area equal to a square with sides 1 decimeter (10 centimeters) long.
1 dm² = 0.01 m² = 100 cm².
It is commonly used to measure small surfaces, such as the area of tiles or sheets of paper.
Square Perch
A square perch is a traditional unit of area, also known as a square rod or pole. It represents the area of a square with sides one perch (rod) long.
1 perch (rod) = 16.5 feet
1 square perch = 16.5 ft × 16.5 ft = 272.25 square feet ≈ 25.29 square meters
160 square perches = 1 acre
Square perches were commonly used in land surveying and property descriptions, especially in the UK and older US records.