Why does the RMS Voltage have a square root of 2?

What is the rms voltage? Why is there a square root of 2? Why is the average of sin^2 equal to 1/2?
Here is the python code I used
trinket.io/glowscript/4678df20c6

[@fizixx]

That's fun.....I like the deconstructing and then doing things with the pieces.

[@donegal79]

excellent, thank you