712 The excircles
26.1 Feuerbach theorem ..................
The nine-point circle is tangent internally to the incircle and externally
to each of the excircles.
A
B C
Fc
Fa
Fb
I
N
F
712 The excircles
The nine-point circle is tangent internally to the incircle and externally
to each of the excircles.
A
B C
Fc
Fa
Fb
I
N
F