As shown in the figure, △ ABC, D is the midpoint of BC, e and F are two points on the edge of AB and AC respectively, ed ⊥ FD, which proves that be + CF > EF

As shown in the figure, △ ABC, D is the midpoint of BC, e and F are two points on the edge of AB and AC respectively, ed ⊥ FD, which proves that be + CF > EF

It is proved that: extend FD to point m, make MD = FD, connect BM, EM, ∵ D as the midpoint of BC, ∵ BD = CD, in △ FDC and △ MDB, FD = DM, ≌ FDC ≌ mdbcd = BD, ≌ FDC ≌ MDB (SAS), ≌ BM = CF, and ∵ FD = DM, ed ⊥ MF, ≁ ED is the vertical line of MF ≁ EF = em, in △ EBM, be + BM >