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Hyacinthos · We discuss themes on Triangle Geometry

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  • Members: 391
  • Category: Geometry
  • Founded: Dec 22, 1999
  • Language: English
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Messages 20782 - 20811 of 21025   Oldest  |  < Older  |  Newer >  |  Newest
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20782 Antreas Hatzipolakis
xpolakis Offline Send Email
Feb 1, 2012
10:01 am
2012/2/1 Alexey Zaslavsky <zasl@...> ... ... and which is the locus of the point of concurrence, as P moves on the Euler line? APH [Non-text portions...
20783 Alexey Zaslavsky
zasl@... Send Email
Feb 1, 2012
1:09 pm
... ... and which is the locus of the point of concurrence, as P moves on the Euler line? The quartic, see the message of Nikos. Using the inversion with...
20784 Antreas
xpolakis Offline Send Email
Feb 2, 2012
7:55 am
2012/2/1 Alexey Zaslavsky <zasl@...> ... Is this true as well? Let ABC be a triangle AoBoCo the medial triangle, P a point on the Euler line and...
20785 Antreas
xpolakis Offline Send Email
Feb 3, 2012
5:58 pm
http://anthrakitis.blogspot.com/2012/02/six-circles.html <http://anthrakitis.blogspot.com/2012/02/six-circles.html> APH [Non-text portions of this message have...
20786 Antreas
xpolakis Offline Send Email
Feb 4, 2012
4:50 pm
Cosmin Pohoata and Vladimir Zajic: On a Mixtilinear Coaxality Abstract It is known that the three Apollonius circles, each passing through a vertex and its...
20787 César Lozada
cesar_e_lozada Offline Send Email
Feb 6, 2012
7:54 pm
Dear geometers: Please, Could someone check and confirm this? Let AH, BH and CH be the orthic triangle of ABC with orthocenter H. Let A1 be the point where AAH...
20788 Antreas Hatzipolakis
xpolakis Offline Send Email
Feb 6, 2012
8:16 pm
You can find more points if you take the excentral triangle IaIbIc instead of your ABC and ABC instead of your orthic. APH ... [Non-text portions of this...
20789 Francisco Javier
garciacapitan Offline Send Email
Feb 6, 2012
8:51 pm
Dear César, some remarks: * First point is ((S^2 + 3 SB SC)/(S^2 + SB SC): ... : ... ) * Second point is ((3 S^2 + SB SC)/(SA (S^2 + SB SC)): ... : ...) * The...
20790 César Lozada
cesar_e_lozada Offline Send Email
Feb 6, 2012
9:13 pm
Thanks, Francisco. Are my calculations wrong? Regards. _____ De: Hyacinthos@yahoogroups.com [mailto:Hyacinthos@yahoogroups.com] En nombre de Francisco Javier ...
20791 Francisco Javier
garciacapitan Offline Send Email
Feb 6, 2012
9:30 pm
No, you're right. I simply supplied another form. Best regards, Francico Javier....
20792 Antreas
xpolakis Offline Send Email
Feb 6, 2012
11:40 pm
1. Let ABC be a triangle, P a point, and Pa,Pb,Pc the orth. projections of P on the altitudes ha,hb,hc resp. Which is the locus of the circumcenter of the...
20793 Antreas Hatzipolakis
xpolakis Offline Send Email
Feb 7, 2012
12:05 am
... Also, which is the locus of NPC center of PaPbPc, as P moves on the circumcircle? ... [Non-text portions of this message have been removed]...
20794 Randy Hutson
rhutson2 Online Now Send Email
Feb 7, 2012
12:23 am
1. Locus is the NPC 2. Locus is the circumcircle If, for 1., orthocenter is substituted for circumcenter, the locus is an ellipse centered at X(185), and major...
20795 Randy Hutson
rhutson2 Online Now Send Email
Feb 7, 2012
12:28 am
This gives another ellipse, centered at non-ETC (search 6.133993655805222), and axes parallel to the other 2. Randy ... [Non-text portions of this message have...
20796 rhutson2 Online Now Send Email Feb 7, 2012
1:46 am
And for incenter, the locus is an ellipse centered at non-ETC (search 4.213190273696852) and major axis meeting line at infinity at X(3308). For symmedian...
20797 Alexey Zaslavsky
zasl@... Send Email
Feb 7, 2012
6:08 am
Dear colleagues! You can order paper version of the jcg on amazon. http://www.amazon.com/gp/product/1469941058/ Also please don't forget to send us your new...
20798 Antreas Hatzipolakis
xpolakis Offline Send Email
Feb 7, 2012
7:37 am
It seems that for any point Q = (x:y:z) with respect PaPbPc, the locus of Q is a conic (an ellipse / circle) as P moves on the circumcircle. Anyway, which is...
20799 Antreas Hatzipolakis
xpolakis Offline Send Email
Feb 7, 2012
7:41 am
... How about a synthetic proof that, if P lies on the circumcircle of ABC, then the circumcenter of PaPbPc lies on the NPC of ABC? APH Which is the locus of...
20800 rhutson2 Online Now Send Email Feb 7, 2012
3:31 pm
One generalization seems to be: If X(i) of ABC lies on the Euler line of ABC, then the locus of X(i) of PaPbPc is an ellipse with center on line...
20801 Nikolaos Dergiades
ndergiades Offline Send Email
Feb 7, 2012
3:39 pm
Dear Antreas, ... The circumcenter is the midpoint of HP and hence the locus the NPC. ND...
20802 rhutson2 Online Now Send Email Feb 7, 2012
5:28 pm
Another interesting result: for X(i), i=2,4,5 (and presumably any others on Euler line), the corresponding vertices of the locus ellipses are collinear, with...
20803 Antreas Hatzipolakis
xpolakis Offline Send Email
Feb 7, 2012
6:13 pm
... and who knows if we have similar interesting results if we take Pa,Pb, Pc as orth. projections on cevians of point P other than H! Thanks APH ... ...
20804 Antreas Hatzipolakis
xpolakis Offline Send Email
Feb 8, 2012
8:29 pm
In the case of the altitudes, ie cevian / pedal triangle of H, the perpendiculars from a point P to cevians AH,BH,Ch are also parallels to sidelines of ABC. ...
20805 rhutson2 Online Now Send Email Feb 9, 2012
12:02 am
Dear Hyacinthists, From the first 2 definitions of Antigonal at http://bernard.gibert.pagesperso-orange.fr/gloss/pointsandmapping.html, an analog using...
20806 Antreas
xpolakis Offline Send Email
Feb 9, 2012
11:25 am
http://anthrakitis.blogspot.com/2012/02/perspective.html <http://anthrakitis.blogspot.com/2012/02/perspective.html> APH [Non-text portions of this message have...
20807 rhutson2 Online Now Send Email Feb 9, 2012
3:02 pm
The choice of A1 and A2, etc. appears to depend on the shape of ABC. For example, for the ETC ref. triangle, it is A1B1C2 that is perspective to ABC at...
20808 Francisco Javier
garciacapitan Offline Send Email
Feb 9, 2012
7:08 pm
Yes, so, here is more precise information: The line A"H intersect the circumcircle at point A1, A2 with coordinates A1: {a^2 (a^2+b^2-c^2) (a^2-b^2+c^2)...
20809 Antreas Hatzipolakis
xpolakis Offline Send Email
Feb 9, 2012
9:49 pm
Generalization: Is it true if we replace O with a point P? (The perspector on the HP line) APH ... [Non-text portions of this message have been removed]...
20810 Chandan Banerjee
cbanerjee.2011 Offline Send Email
Feb 10, 2012
7:14 am
Yes, it is true even if you replace O by P, It follows from the following problem:- It follows from the following problem which is a generalisation of a ...
20811 Antreas
xpolakis Offline Send Email
Feb 10, 2012
7:23 pm
.... and the most natural question in the world is what properties the A2,B2,C2 have?? Do we have a Picasso-like circle, which, If true (as I think), I will ...
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