# Nagel Point
Let(A=[-u1,0], B=[u1,0], C=[u2,u3], O=[x1,x2], A1=[x3,x4], B1=[x5,x6], 
    C1=[x7,0]):
Nagel := Theorem(
   [arbitrary(A,B,C), equiangle(C,A,O,O,A,B), equiangle(A,B,O,O,B,C),
    perpfoot(O,A1,B,C,A1), perpfoot(O,B1,A,C,B1), perpfoot(O,C1,A,B,C1),
    oncircle(A1,B1,C1,C1)], concurrent(A,A1,B,B1,C,C1),
   [x1,x2,x3,x4,x5,x6,x7]);
