If a square root is ration or irrational?
A square root is rational if it can be expressed as a ratio of two integers (a fraction with an integer in the numerator and an integer in the denominator).
The easiest way to check this is by converting the square root to a decimal. If there are an infinite number of digits after the decimal place AND these digits do not repeat in any predictable pattern, the root is irrational. If there are a finite number of digits, the root can be expressed rationally, or if there are infinite digits in a repeating pattern (1/99 is an example decimal like this), you can can express it rationally.