25.3 Ceva Theorem 707
Example: Nagel point
IfX,Y,Zare the points of tangency of the excircles with the respective
sidelines, the linesAX,BY,CZintersect at the Nagel point.
A
B C
Z
X
Y
s−c s−b
s−a
s−b s−c
s−a Q
X =(0:s−b:s−c)
Y =(s−a:0:s−c)
Z =(s−a:s−b:0)
Q =(s−a:s−b:s−c)