### √2

The **square root** of the number two is

##### Explanation

The ratio between the side and the diameter of a square cannot be written by any pair of whole numbers. So they are incomparable. Because of this √2 is called an irrational number. On your calculator you can see that √2 = 1.4142135... and it lies on the number line between 1 and 2.

Here a length divides the side into 10 equal parts, but the diagonal is divided into 14 equal parts with a small remainder.

## HistoryThe ancient Greek mathematician Hippasus (ca. 530 BC - ca. 450 BC) discovered irrational numbers through geometry. |