|≈||approximately equal to|
|digits||indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …)|
A barn (symbol: b) is a unit of area equal to 10−28 m2 (100 fm2). Originally used in nuclear physics for expressing the cross sectional area of nuclei and nuclear reactions, today it is also used in all fields of high-energy physics to express the cross sections of any scattering process, and is best understood as a measure of the probability of interaction between small particles.
The square yard (Northern India: gaj) is an imperial unit of area, formerly used in most of the English-speaking world but now generally replaced by the square metre, however it is still in widespread use in the U.S., Canada and the U.K. It is defined as the area of a square with sides of one yard (three feet, thirty-six inches, 0.9144 metres) in length.