Most use calculators these days. I assume you want to know without the aid of a calculator. You didn't specify.
I always liked the Babylonian square root method.
\(\displaystyle \L\\\sqrt{1332.25}\)
Take a guess and start with that. 36 is pretty close.
\(\displaystyle \L\\\frac{1332.25}{36}=37.007\)
\(\displaystyle \L\\\frac{36+37.007}{2}=36.5035\)
\(\displaystyle \L\\\frac{1332.25}{36.5035}=36.4965\)
\(\displaystyle \L\\\frac{36.5035+36.4965}{2}=36.5\)
And there it is.
You can use most anything for an initial guess, but the closer it is the faster it'll converge to the square root.
If you want a lesson on this method, do a search on Babylonian square root method.
