Question

What’s the square root of 2

Answer 1

The square root of 2, by definition of square root, is a number that gives 2 when squared.

So, it's a number defined by the following property:

$\sqrt{2}\cdot\sqrt{2} = (\sqrt{2})^2 = 2$

It is a decimal, non-period number, so we can only approximate its value, which is

$\sqrt{2} \approx 1.41421356237\ldots$

Answer 2

Since you multiply it by itself, you should get four.