As shown in the figure, ∠ ACB = 90 ° in △ ABC, ad bisects ∠ BAC, de ⊥ AB in E

As shown in the figure, ∠ ACB = 90 ° in △ ABC, ad bisects ∠ BAC, de ⊥ AB in E

It is proved that: ∵ de ⊥ AB, ∵ AED = 90 ° = ∠ ACB, and ∵ ad bisecting ∵ BAC, ∵ DAE = ∠ DAC, ∵ ad = ad, ≌ ACD, ≌ AE = AC, ∵ ad bisecting ≁ BAC, ≁ ad ⊥ CE, that is, the straight line ad is the vertical bisector of the line CE