The number I want to talk about now is the square root of 2.
My favorite fact about root 2, well.
If you take the A series of paper, so this is A4 paper.
It's pretty standard in most of the world.
If you take a piece of paper like this.
If you look at the ratio between the long edge and the short edge, which means if you measure the long edge, And you divide by the short edge, it will be the square root of 2 and they picked this on purpose.
The square root of 2 is about 1.41 something or other.
And it's the number you get if you work with Pythagoras' Theorem, Which said that if you have a unit length along there, and a unit length along there.
So this length, the square of this length plus the square of that is that.
This length is root 2; it's the square root of 2.
