A square pole, also known as a square perch, is an obsolete unit of land area measurement that was historically used in some English-speaking countries, including the United States and the United Kingdom. It is part of the older system of land measurement.
One square pole is equivalent to one square perch. In terms of modern measurements, one square pole is approximately equal to 25.29285264 square meters (m²) or 0.00625 acres.
As with other outdated units of land area measurement, the square pole is no longer commonly used in modern land transactions or legal documents. More standardized systems of measurement, such as square meters and square feet, have largely replaced these units.
A circular mil (often abbreviated as cmil or kcmil) is a unit of area used primarily in the United States for measuring the cross-sectional area of a round wire or cable. It is a convenient unit for specifying the size of electrical conductors.
One circular mil is equal to the area of a circle with a diameter of one mil (1/1000th of an inch) or approximately 0.000000506707 square inches (in²). In metric units, one circular mil is approximately equal to 0.000001273 square millimeters (mm²).
Circular mils are commonly used in the American Wire Gauge (AWG) system to specify wire sizes. The AWG system assigns a unique number to each wire size, and this number is related to the wire's cross-sectional area in circular mils. For example, a larger AWG number corresponds to a smaller wire size with fewer circular mils, while a smaller AWG number corresponds to a larger wire size with more circular mils. This system allows for easy reference and selection of wire sizes for various electrical applications.