✨ 最佳解答 ✨ Mer 約2年以前 OB₁ : B₁B = OA₁ : A₁A = 6:2 = 3:1 OA₁ : A₁A = OB₂ : B₂B₁ = 3:1 所以OB₂ = 6*(3/4) = 9/2,B₂B₁ = 3/2 OB₂ : B₂B₁ = OA₂ : A₂A₁ = (9/2):(3/2) = 3:1 = OB₃ :B₃B₂ OB₃ = (9/2)*(3/4) = 27/8 留言