perplexus.info :: Geometry : Counting Crossings

Counting Crossings (Posted on 2014-10-08)

3 lines in a plane can be easily be drawn such that there are 0, 1, 2 or 3 points where at least 2 of them cross.

What are the possible numbers of crossing points for 4, 5, or 6 lines?

Can any of these results be generalized?

No Solution Yet Submitted by Jer

Rating: 4.0000 (1 votes)

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Subject	Author	Date
re: Other possibilities for 6 lines, and a theorem (unproven)	Dej Mar	2014-10-10 04:31:12
Other possibilities for 6 lines, and a theorem (unproven)	Steve Herman	2014-10-09 07:55:09
wording	Charlie	2014-10-09 07:51:57
To sleep, perchance to dream	Steve Herman	2014-10-08 21:49:15
Are the solutions correct?	Jer	2014-10-08 14:29:43
solution	Charlie	2014-10-08 13:12:45
solution	Ady TZIDON	2014-10-08 13:02:14

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