Q:

What is difference between "as" and "as to"?

Both them are being used to handle same process in the sentence. For example;
I : Circle is called as geometric shape.
II: Circle is called as to geometric shape.
Google translate converts these two sentences into the Turkish as same. In addition, It converts both "as" and "as to" to same word in Turkish. What is the difference between them exactly? Which sentences above is it used commonly? I or II. Or does these two sentences have different meanings?

A:

It is difficult to answer this, as neither of the examples you give sound like natural examples of English and, at least out of context, they don't seem to mean anything.
In general:

"as" has many meanings, but often it means "like" or "because"
"as to" means "about" in the sense of "regarding", i.e. setting a topic, and is not used often in English

You can find more detailed explanations of the words with examples from a dictionary - these definitions of as and as to from Cambridge Dictionaries Online also have Turkish translations.

