Method 1 - How to remember the 30 - 60 - 90 triangle ratio rule

How to remember the ratio of the sides are 1, `root()3`, 2.

This is easy to remember if you start from the fundamentals. Start with an equilateral triangle.

Split this triangle in half.

Turn one triangle on its side.

And ? is easily solved using the Pythagoras theorem.

`2^2=1^2+?^2`

`4-1=?^2`

`?^2=3`

`?=root()3`

So we can finish the 30 - 60 - 90 triangle ratio. 

or in any length ratio.