解:(1) ∵ME垂直平分AB ∴MA = MB·············································································· 1分 ∵NF垂直平分AC ∴NA = NC··············································································· 2分 ∴cm······················· 4分 (2) ∵AB = AC, ∴······································································· 4分 ∵MA = MB ∴··································································· 5分 ∵NA = NC ∴··································································· 6分 ∴·········································· 8分 (3) 能.理由如下:·········································································· 9分 ∵MA = MB ∴∠MAB =∠B ∵NA = NB ∴∠NAC =∠C ∴ ·································· 12分 |