The triangle line that passes through the inner and outer Soddy centers S and S'. The Soddy line is central line L_657 and has trilinear equation (γ - β)/((-a + b + c) a) + (α - γ)/((a - b + c) b) + (β - α)/((a + b - c) c) = 0.

de Longchamps point | Euler-Gergonne-Soddy triangle | Euler line | first Eppstein point | Fletcher point | Gergonne point | Griffiths points | harmonic range | incenter | Rigby points | second Eppstein point | Soddy centers