∀ {V : Type u_1} {P : Type u_2} [inst : NormedAddCommGroup V] [inst_1 : InnerProductSpace ℝ V] [inst_2 : MetricSpace P]
  [inst_3 : NormedAddTorsor V P] (t : Affine.Triangle ℝ P) {i₁ i₂ : Fin 3},
  i₁ ≠ i₂ →
    dist (Affine.Simplex.circumcenter t)
        ((EuclideanGeometry.reflection (affineSpan ℝ (t.points '' ↑{i₁, i₂}))) t.orthocenter) =
      Affine.Simplex.circumradius t