The outer Soddy center (or outer Soddy point) is the center of the outer Soddy circle. It is equivalent to the isoperimetric point X_176 and has equivalent triangle center functions α_176 | = | -1 + sec(1/2 A) cos(1/2 B) cos(1/2 C) α_176 | = | -1 + (b c)/(2(-a + b + c) R), where R is the circumradius of the reference triangle. It lies on the Soddy line.

inner Soddy center | outer Soddy circle | Soddy circles