A square yard (sq yd or yd²) is a unit of area commonly used in the United States and a few other countries. It is defined as the area of a square with sides that each measure one yard (3 feet) in length.
In terms of square feet, one square yard is equal to 9 square feet (1 yard * 1 yard = 3 feet * 3 feet = 9 square feet).
In terms of square meters, one square yard is approximately equal to 0.836127 square meters.
Square yards are often used in various applications, including real estate, landscaping, and construction, especially in the United States where the customary system of measurements is still prevalent.
A square mil (abbreviated as sq mil or mil²) is a unit of area measurement used primarily in the United States for very small areas, especially in the context of electrical engineering and wire gauge measurements. One square mil is equal to one square thousandth of an inch or one square mil (0.000001 square inches).
In terms of modern metric units, one square mil is approximately equal to 6.4516 square micrometers (µm²) because there are 25.4 micrometers in one thousandth of an inch (1 mil).
Square mils are often used when specifying the cross-sectional area of wires, particularly in electrical and electronic engineering. For example, the American Wire Gauge (AWG) system uses square mils to represent the cross-sectional area of wires, with smaller wire sizes having fewer square mils, and larger wire sizes having more square mils.