The square root of 2 (√2) is an irrational number, meaning it cannot be exactly expressed as a fraction of two integers. Its decimal approximation is:

$\sqrt{2} \approx 1.414213562$

This number is significant in mathematics, especially in geometry, where it represents the length of the diagonal of a square with side length 1, based on the Pythagorean theorem.

Would you like more details about the properties of irrational numbers or how √2 is used in different areas of math?

Here are five related questions:

1. How is the square root of 2 derived geometrically?
2. Why is √2 classified as an irrational number?
3. What is the significance of √2 in the Pythagorean theorem?
4. How is √2 used in trigonometry?
5. Can √2 be approximated using fractions?

Tip: When working with √2 in calculations, it is often useful to use its decimal approximation up to a few decimal places (1.414) for quicker results without losing much precision.