For right angled triangles it is the square root of square of side A added to square of side B (sorry i don't have a square sign on my keyboard) hypotenuse=square root of AxA+BxB
There are a couple of ways to write 5.229: Five point two two nine Five and two hundred twenty-nine thousandths
There are a couple of ways to write 9.761: Nine point seven six one Nine and seven hundred sixty-one thousandths.
You could write it in at least two different ways: twelve and thirty nine thousandths, or twelve point zero three nine.
If you want a mathematical way to solve square roots that isn't trial and error, you probably need an algorithim. There are many ways to do this, and if you aren't satisfied with my way, or don't understand search for square root algorithims and you will find millions of ways.
There are two ways that are acceptable: Thirty-nine or Thirty nine
nine 9
You could write 64.9 a couple of ways: Sixty-four point nine Sixty-four and nine tenths.
The square root of 100 is: ± 10, because 10 x 10 = 100 and -10 x -10 = 100The square root of 100 is 10.
For right angled triangles it is the square root of square of side A added to square of side B (sorry i don't have a square sign on my keyboard) hypotenuse=square root of AxA+BxB
You measure it. Or you take a quarter of the perimeter of the square. Or the square root of the area of the square. Or there are other ways, depending on what information you have.
There are two ways that are acceptable: Thirty-nine or Thirty nine
Nine elevenths, 9/11, 0.8181 repeating, 81.82%
There are a couple of ways to write 8.639. Eight point six three nine Eight and six hundred thirty-nine thousandths.
There are a couple of ways to write 5.229: Five point two two nine Five and two hundred twenty-nine thousandths
There are a couple of ways to write 9.761: Nine point seven six one Nine and seven hundred sixty-one thousandths.
You could write it in at least two different ways: twelve and thirty nine thousandths, or twelve point zero three nine.