According to the nature of the vertical line, BE=OE and FC=OF.
In the equilateral triangle ABC
∠ABC=∠ACB=60
∫OB and OC are bisectors of∠ b and∠ c respectively.
∴∠OBE=∠BOE=30,∠COF=∠FCO=30
In △OBC, ∠ BOC =180-∠ OBE-∠ FCO =120.
∴∠eof=∠boc-∠boe-= 180-∠OBE-∠cof = 120-60 = 60
Similarly ∠ BeO = ∠ CFO = 120.
Available ∠ OEF = ∠ OFE = 60.
△OEF is an equilateral triangle
∴OE=OF
Then BE=EF=FC