Assignment 1 questions.

Would it be ok to determine if a stroke is a circle by seeing if each
coordinate has a matching coordinate directly across from it?  This would
distinguish a circle from a line, but would not distinguish a circle from a
square.

  You should take a pragmatic approach to questions like this: if it works it's
  ok; if it doesn't work then it's not.

  The difficulty I see (after thinking about it for all of a minute or so) is
  trying to figure out what "directly across" means.  Another difficulty I see
  (if I understand you correctly) is that you may be begging the question;
  "directly across" make sense with respect to circles but not lines, so you
  have to determine if a stroke is a circle or a line before you can apply your
  test to see if the stroke is a circle or a line.

  I don't want to discourage you, it may turn out to be a good approach; you've
  thought about it longer than I have.  But if you can't handle these two
  difficulties, the approach probably isn't fruitful.  I will say there are
  simpler approaches to distinguishing circles from lines.

  And remember, you have to distinguish circle-like strokes from line-like
  strokes, you don't have to distinguish between different kinds of circle-like
  strokes.