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) = bc[a2(b2 + c2 - 2a2) + (b2 - c2)2]/(b2 + c2 - a2)
Barycentrics g(a,b,c) : g(b,c,a) : g(c,a,b), where g(a,b,c) = [a2(b2 + c2 - 2a2) + (b2 - c2)2]/(b2 + c2 - a2)
X(1990) is described in section 6.4.2 of the downloadable article cited at X(1989).
X(1990) lies on these lines:
4,6 44,1785 50,112 140,216 186,1138 230,231 297,340 395,471 396,470 403,1989 458,597 550,577 1033,1609
X(1990 = midpoint of X(297) and X(648)
X(1990) = X(I)-Ceva conjugate of X(J) for these (I,J): (2,133), (1300,25), (1989,53)
X(1990) = crosspoint of X(2) and X(1294)