# Feuerbach Theorem
Let(A=[-1,0], B=[1,0], C=[u1,u2], Ie=[x1,x2], Ma=[x3,x4], Mb=[x5,x6],
    Mc=[x0,0], N=[x7,x8]):
Feuerbach := Theorem(
    [arbitrary(A,B,C), equiangle(C,A,Ie,Ie,A,B), equiangle(C,B,Ie,Ie,B,A),
     midpoint(B,C,Ma), midpoint(C,A,Mb), midpoint(A,B,Mc),
     circumcenter(Ma,Mb,Mc,N), x9^2-sdistance(N,Mc), x10^2-sdistance(Ie,N)],
    (x10-x9-x2)*(x10-x9+x2)*(x10+x9-x2)*(x10+x9+x2),
    [x1,x2,x3,x4,x5,x6,x0,x7,x8,x9,x10]);
