As shown in the figure, AC ∥ BD, ab ∥ CD, ∥ 1 = ∥ e, ∥ 2 = ∥ F, AE intersects CF at point O, try to explain: AE ⊥ CF

As shown in the figure, AC ∥ BD, ab ∥ CD, ∥ 1 = ∥ e, ∥ 2 = ∥ F, AE intersects CF at point O, try to explain: AE ⊥ CF

It is proved that: ∵ AC ∥ BD, ∵ Cao = ∥ e, ∵ ACO = ∥ F, ∵ 1 = ∥ e, ∥ 2 = ∥ F, ∥ 1 = ∥ Cao = 12 ∥ BAC, ∥ 2 = ∥ ACO = 12 ∥ ACD, ∥ ab ∥ CD, ∥ BAC + ∥ ACD = 180 °, ∥ CaO + ∥ ACO = 90 °, ∥ AOC = 90 ° and ≁ AE ⊥ CF