How to find the square root of 5??

Can you explain better what you want to know?
root 5 is an irrational number which means that it cannot be written exactly as a fraction or a decimal.
You can get an estimate from your calculator.
I probably haven't answered your question.

The estimated square root of 5 is the square root of 4 which is 2.
The real number for it is 2.2360679775.

root 2 is an irrational number. 2.2360679775 is still an approximation.