Interactive Applet |
You can move the points A, B and C (click on the point and drag it).
Press the keys “+” and “−” to zoom in or zoom out the visualization window and use the arrow keys to translate it.
You can also construct all centers related with this one (as described in ETC) using the “Run Macro Tool”. To do this, click on the icon , select the center name from the list and, then, click on the vertices A, B and C successively.
Information from Kimberling's Encyclopedia of Triangle Centers |
Trilinears f(A,B,C) : f(B,C,A) : f(C,A,B),
where f(A,B,C) = (1 - cos A)/cos2A
Barycentrics (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)Let A'B'C' be the intouch triangle of ABC. Let Ca be the point other than C' in which the perpendicular to BC from C' meets the incircle, let Ba be the point other than B' in which the perpendicular to BC from B' meets the incircle, and let A0 be the point of intersection of lines BCa and CBa. Define B0 and C0 cyclically. Then triangle A0B0C0 is perspective to ABC, and the perspector is X(1118). (Antreas Hatzipolakis, #5321, 4/30/02)
X(1118) lies on these lines:
4,65 7,286 12,281 19,208 20,243 24,108 28,56 34,207 92,388X(1118) = isogonal conjugate of X(1259)
X(1118) = isotomic conjugate of X(1264)