Why is the US Flag folded into a triangle?

[le Voyageur 72]

My own research dovetails with Smithsonian's in that I can safely say...."we don't know'.  About the best we can do is to state, is that the triangle fold first appeared about 1917.  Trying to glean reasons from 18th and 19th century quartermaster inventories, as well as those of militia units were dead ends.  Old Glory was simply folded the same as a bed sheet, or rolled up.

However, there is a hypothesis, which is, is that we're dealing with a Mason's  hat trick (no disrespect intended being that it was hugely clever if this is the case). The first clue can be found on the back of the One Dollar Bill.  Additionally, an early Jewish - Christian symbol was the chevron and circle which can be seen on the Talpot tomb,  supposedly symbolizing the House of David. However, the symbol is far older then that harking back to the Egyptians where this symbol represented protection, royal power and good health.