Skip to search.
Hyacinthos · We discuss themes on Triangle Geometry

Group Information

  • Members: 391
  • Category: Geometry
  • Founded: Dec 22, 1999
  • Language: English
? Already a member? Sign in to Yahoo!

Yahoo! Groups Tips

Did you know...
Message search is now enhanced, find messages faster. Take it for a spin.

Messages

  Messages Help
Advanced
Messages 19382 - 19411 of 21025   Oldest  |  < Older  |  Newer >  |  Newest
Messages: Simplify | Expand   (Group by Topic) Author Sort by Date ^
19382 jpehrmfr Offline Send Email Nov 1, 2010
11:11 am
Dear Giovanni, you wrote ... and the trace of another median, construct the triangle." ... some time on it I don't know even if it is solvable by ruler and...
19383 ForumGeom
ForumGeom@... Send Email
Nov 1, 2010
4:55 pm
The following paper has been published in Forum Geometricorum. It can be viewed at http://forumgeom.fau.edu/FG2010volume10/FG201015index.html The editors Forum...
19384 zeroprof Offline Send Email Nov 2, 2010
6:58 pm
Many thanks Jean-Pierre. I'm wondering how you find that the locus is a circular cubic: by algebra or from other considerations? Best regards Giovanni Artico...
19385 Antreas
xpolakis Offline Send Email
Nov 2, 2010
9:18 pm
... In other words: Let ABC be a triangle and A'B'C' the circumcevian triangle of G. To construct ABC if are given A, A', B'(or C'). An easier and...
19386 Philippe
chephip Offline Send Email
Nov 2, 2010
10:56 pm
... Dear Antreas, That's pretty obvious, isn't it ? (Dilation of line AA' from center B and ratio 2 intersects circumcircle of AA'B in C) Some other related...
19387 Nikolaos Dergiades
ndergiades Offline Send Email
Nov 3, 2010
2:55 am
Dear friends, is there an easy construction of the conic bc(b-c)xx + caayy + c(aa+bb-cc)xy -baazz - b(aa+cc-bb)xz = 0 in barycentrics? Best regards Nikos...
19388 Francisco Javier
garciacapitan Offline Send Email
Nov 3, 2010
5:56 am
Dear Nikos, Your conic is a circle. Let the internal and external bisector of angle A intersect BC at L and L' respectively. Then L' is the center of the...
19389 Antreas Hatzipolakis
xpolakis Offline Send Email
Nov 3, 2010
6:52 am
Dear Philippe Right (and there are two solutions). I had in mind another solution: Let M be the midpoint of CB. The locus of M as C moves on the circle (AA'B)...
19390 Nikolaos Dergiades
ndergiades Offline Send Email
Nov 3, 2010
7:08 am
Dear Francisco. Very good. Thank you. The three analogous circles pass through the same point (I don't know the barycentrics) and I was expecting the isogonal ...
19391 Francisco Javier
garciacapitan Offline Send Email
Nov 3, 2010
8:13 am
Dear Nikos: Your A-circle is the locus of points P such that PB^2/PC^2 = AB/AC; this easily implies that if P is on the A-circle and on the B-circle the P also...
19392 Antreas Hatzipolakis
xpolakis Offline Send Email
Nov 3, 2010
9:02 am
On Wed, Nov 3, 2010 at 10:12 AM, Francisco Javier ... How about the locus of P such that PB/PC = AB^2/AC^2 (and the other two similar)? APH [Non-text portions...
19393 jpehrmfr Offline Send Email Nov 3, 2010
9:56 am
Dear Nikolaos ... I think that the point that maximizes xy+yz+zx is the Mittenpunkt X[9] with maximal values rss/(r+4R) (s=semi-perimeter) If fact xy+yz+zx = k...
19394 Nikolaos Dergiades
ndergiades Offline Send Email
Nov 3, 2010
10:02 am
Dear Clark Kimberling and friends, having in mind your Hyacinthos message 18379 and your question at the end of your last FG paper "Trilinear Distance...
19395 Nikolaos Dergiades
ndergiades Offline Send Email
Nov 3, 2010
10:04 am
Dear Jean-Pierre, Thank you. Yes. I found this just before an hour. Best regards Nikos Dergiades...
19396 Antreas
xpolakis Offline Send Email
Nov 3, 2010
10:30 am
A mathematics teacher asks a student: -- When are two triangles congruent? Student: -- When they were made by the same confectioner! (zaxaroplastis) The...
19397 Francisco Javier
garciacapitan Offline Send Email
Nov 3, 2010
11:34 am
In the general case of PB/PC = (AB/AC)^n the A-circle is centered at (0:-b^n:c^n) and has squared radius (a^2 b^n c^n)/(b^n - c^n)^2. This circle intersect the...
19398 Francisco Javier
garciacapitan Offline Send Email
Nov 3, 2010
11:37 am
Correction: ... This circle intersects the line BC at (0:b^(n/2):c^(n/2)) and (0:- b^(n/2):c^(n/2))....
19399 Nikolaos Dergiades
ndergiades Offline Send Email
Nov 3, 2010
12:34 pm
Dear Antreas Do you mean that the student is used to triangles of Panorama and hence is from Thessaloniki? Nikos...
19400 Antreas Hatzipolakis
xpolakis Offline Send Email
Nov 3, 2010
12:44 pm
... Dear Nikos, http://thodorikorfi.blogspot.com/2010/11/blog-post_03.html ... -- http://anopolis72000.blogspot.com/...
19401 chris.vantienhoven
chris.vantie... Offline Send Email
Nov 3, 2010
2:25 pm
Dear Nikos and Francisco, 1. Francisco, your point N is also Intersectionpoint BC with A.X366. 2. There are 2 points as intersectionpoint of the 3 circles. ...
19402 Bernard Gibert
bernardgibert Offline Send Email
Nov 4, 2010
4:34 am
Dear friends, according to ETC, the points with trilinears cos(A/3 + t) : : and sin(A/3 + t) : : should lie on the line X(16), X(358). I suspect that X(16) is...
19403 Nikolaos Dergiades
ndergiades Offline Send Email
Nov 4, 2010
5:56 pm
Dear Bernard, the point X(16) (sin(A -pi/3) : sin(B -pi/3) : sin(C -pi/3)) and the points (sin(A/3 + M) : sin(B/3 + M) : sin(C/3 + M)) (cos(A/3 + N) : cos(b/3...
19404 Nikolaos Dergiades
ndergiades Offline Send Email
Nov 4, 2010
6:00 pm
I repeat with a correction to a sign Dear Bernard, the point X(16) (sin(A -pi/3) : sin(B -pi/3) : sin(C -pi/3)) and the points (sin(A/3 + M) : sin(B/3 + M) :...
19405 Nikolaos Dergiades
ndergiades Offline Send Email
Nov 4, 2010
6:20 pm
Dear Bernard, I forgot to say that the factorization (x-y)(y-z)(z-x)(1+xy)(1+yz)(1+zx)Q.R contains the factor (1+mn) and that the determinant of points (sin(A...
19406 Bernard Gibert
bernardgibert Offline Send Email
Nov 4, 2010
6:59 pm
Dear Francisco and Nikolaos, thank you for your answers that infirm what I had suspected. however, I'm still unhappy about this for two reasons : 1. the proofs...
19407 Antreas Hatzipolakis
xpolakis Offline Send Email
Nov 4, 2010
7:33 pm
... Natural question. Perhaps X(15) is involved in another collinearity with points cos(A/6 + t) ::, sin(A/6 + t) ::, or something similar. aph [Non-text...
19408 Nikolaos Dergiades
ndergiades Offline Send Email
Nov 4, 2010
10:28 pm
Dear Bernard, here is a proof without computer. If a = A/3, b = B/3, c = C/3, p = pi/3 = a + b + c then the trilinears of the 3 points X(16), P, Q are sin(3a -...
19409 bbblow Offline Send Email Nov 5, 2010
9:11 am
Dear Triangle Geometers, Fermat point is the for real numbers t,u,v, identifying the point such that tAP+uBP+vCP takes extreme value can be considered as the...
19410 Kafka Catalin
kafka_mate Offline Send Email
Nov 5, 2010
10:48 am
Dear Sung Hyun,  I send you some results concerning Fermat points (unfortunately are in Romanian, but you can use google translator). Best regards, Catalin...
19411 Luís Lopes
qedtexte Offline Send Email
Nov 5, 2010
4:37 pm
Dear Hyacinthists, \pm means + - Do the problems A,a,r_b\pm r have a R&C construction? As always, thank you for your valuable time/information. Luis [Non-text...
Messages 19382 - 19411 of 21025   Oldest  |  < Older  |  Newer >  |  Newest
Add to My Yahoo!      XML What's This?

Copyright © 2010 Yahoo! Inc. All rights reserved.
Privacy Policy - Terms of Service - Guidelines NEW - Help