Continuous symmetry groups are mathematically represented by matrices -- rectangular arrays of numbers -- which can convert the properties of the mathematical object into linear algebra.

Firstly, the math behind quantum physics makes extensive use of matrices—rectangular arrays of numbers.

A history of prime numbers Informally, a positive counting number larger than one is prime if that number of dots can be arranged only into a rectangular array with one column or one row. For ...

For example, 11 is a prime number since 11 dots form only rectangular arrays of sizes 1 by 11 and 11 by 1. Conversely, 12 is not prime since you can use 12 dots to make an array of 3 by 4 dots ...