The Origin of Arabic Numbers?

A Moroccan acquaintance of mine sat down and tried to convince me that the origin of Arabic numbers has to do with angles.

He claimed if we look at how the original numbers looked, and placing a dot on each angle, you can see how each symbol has the corresponding number of angles:

While this is interesting, I will have to file it under "apocryphal". First, the 5 has a tail and the 7 has a "base" (I conceded that people use a hash on it in many parts of the world). I also find it hard to believe that a writer of 9 had to draw an octagon (the reply being that is one of the many reasons the digits were simplified over time).

A quick web search didn't find any corroborating data, but I didn't spend a lot of time looking. It's interesting, if true, and even if it isn't true, it makes a good story to tell at a bar on a cocktail napkin.