Learn English – What does “ways out” mean

This is a confusion of two different expressions:

1. as seen, which has a variety of uses:

   Chopin, as seen by his pupils ... = how his pupils saw Chopin
   Professor Hunt discusses Keats' relation as a poet to his Elizabethan forerunners, as seen in his love of nature ... = which may be discerned in his love of nature
   As seen on television ... = the same one or of the sort you see on television

2. to be seen, which as used here means approximately which may be seen

   Uccello's violent one-point perspective, to be seen in his Battle of Romano series.

The author of this passage was not a native speaker; but he was highly educated and a very literate writer. I think his mistake arose because he was trying to say two things at once: that in Marx' day feudalism as a living form was to be seen only in Japan, and that Marx was inviting his readers to examine feudalism of the sort you see in Japan.

By the way: I think you can ignore that Ngram. I glanced at fifty or so the hits and they were all components of different constructions, mostly so as to be = in order to be or so ADJ as to be = so ADJ that it was.

This is the phrasal verb to turn out. It means "to happen" or "to become known to happen in a particular way".

So in this sentence it means that many geometric properties have become known to be...