The term "circular inch" is not a standard unit of measurement within the International System of Units (SI) or any widely recognized system of measurement. It's not commonly used in scientific or engineering contexts.
However, it's possible that the term "circular inch" may be used informally or in specialized industries to describe a measurement related to the circumference or area of a circle, particularly in contexts where precision matters. If you encounter this term, you would need to refer to the specific context or industry where it's being used to understand its meaning and how it is being applied.
A square rod (US survey) is a unit of area measurement used in the United States for land surveying and legal property descriptions. It is different from the standard square rod or square pole and is based on the U.S. survey foot, which is a historical unit of length used in land surveying in the United States. The U.S. survey foot is slightly different from the international foot.
One square rod (US survey) is equal to 1/160th of an acre. In terms of area, this is approximately equal to 25.29285264 square meters (m²) or 0.00625 acres.
This unit is used in land-related applications, especially in the United States, where the U.S. survey square rod is employed for legal and historical reasons in land surveys, property descriptions, and land records. It's important to be aware of the specific units being used when dealing with land measurements in the United States to avoid discrepancies or errors.