Parallel Lines, Concentric CirclesDate: 04/24/2003 at 21:29:03 From: Christina Subject: Parallel lines If parallel means that two lines never intersect, would the lines that form a circle drawn inside another circle be considered parallel? Date: 04/24/2003 at 23:38:48 From: Doctor Peterson Subject: Re: Parallel lines Hi, Christina. Circles are not lines, so they can't be parallel lines. Remember, in math a line is always a straight line. We do sometimes talk about parallel curves, and when we do, concentric circles (not just any circles one inside the other, but circles with the same center) would be called parallel. In that case, though, the definition is not that they are parallel if they don't intersect, but that they are parallel because they are always the same distance apart. In fact, parallel lines are not really defined as any lines that don't intersect. That is only true in a plane. Lines in different planes (such as one edge of your ceiling, and a different edge of your floor) don't intersect, but are not parallel. Parallel lines go in the same direction, and remain the same distance apart everywhere. If you have any further questions, feel free to write back. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/ Date: 04/25/2003 at 11:02:48 From: Christina Subject: Thank you (parallel lines) Thank you for your quick reply! I also appreciate that it is in language that I can easily relay to my students. |
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