## X(1138) (ISOGONAL CONJUGATE OF X(399))

 Interactive Applet

You can move the points A, B and C (click on the point and drag it).
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This applet was built with the free and multiplatform dynamic geometry software C.a.R..

 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/(5 cos A - 4 cos B cos C - 8 cos2A sin B sin C)
Barycentrics    (sin A)f(A,B,C) : (sin B)f(B,C,A) : (sin C)f(C,A,B)

There are only two points X such that the pedal triangle of X is similar to the cevian triangle of X. They are X(4)
and X(1138). (Jean-Pierre Ehrmann, 1/4/03)

X(1138) lies on this line: 30,146

X(1138) = isogonal conjugate of X(399)
X(1138) = isotomic conjugate of X(1272)
X(1138) = X(74)-cross conjugate of X(4)

This is a joint work of
Humberto José Bortolossi, Lis Ingrid Roque Lopes Custódio and Suely Machado Meireles Dias.