As shown in the figure, AE bisects ∠ BAC, BD = DC, de ⊥ BC, EM ⊥ AB, en ⊥ AC

As shown in the figure, AE bisects ∠ BAC, BD = DC, de ⊥ BC, EM ⊥ AB, en ⊥ AC

It is proved that: connect be and EC, ∵ BD = DC, de ⊥ BC ∵ be = EC. ∵ AE bisection ≁ BAC, EM ⊥ AB, en ⊥ AC, EM = en, ≁ EMB = ≁ enc = 90 °. Be = EC, EM = enbe = ECEM = en, ≌ RT ≌ RT ≌ RT ≌ CNE (HL) ≁ BM = CN