I’m assuming you’re trying to find the line AB (basically the distance between point A and B). If that’s the case, since they both have the same x vale, subtract their y values. 14-3 gives you 11, which is the length of line AB
The square root of 2 is irrational. Because 2 is not a perfect square therefore the square root of 2 must be irrational. 1.4 is its approximate to the tenths place. I hope this was helpful