New Kobon triangles

[Alexandre Wajnberg]

Hi,

(Transmitted by Anthony Labarre)

New Kobon triangles (and a bit of theory) found on an interesting japanese
site (in japanese):
http://www004.upp.so-net.ne.jp/s_honma/triangle/triangle2.htm

...where you'll the following links for three figures:

-For n=10, another solution with also 25 triangles (theoretical max = 26):
http://www10.plala.or.jp/rascalhp/image/10-25-2.gif
[there's also another solution, not referring to the not yet at that time
existing Kobon problem, in Branko Grünbaum (1967): "Convex Polytopes" I will
transmit in a while]

-For n=11, a first solution with 32 triangles (theoretical max = 33):
http://www10.plala.or.jp/rascalhp/image/11-32.gif

-For n=15, a beautiful colored version of the existing figure in Mathworld,
showing some internal structures, and the overall symmetry of order 5.


Some explanations here (in japanese but with some figures speaking by
themselves):

*http://www10.plala.or.jp/rascalhp/nlines.htm
*http://www10.plala.or.jp/rascalhp/nlines2.htm
*http://www10.plala.or.jp/rascalhp/nlines3.htm


Have a nice week-end!

Alexandre