∵EF ∥ BC
∴∠OCB=∠OCF,∠OBC=∠OBE
又BO、CO分别是∠BAC和∠ACB的角平分线
∴∠OCF=∠FCO,∠OBC=∠OBE
∴OF=CF,OE=BE
∴△AEF的周长=AF+OF+OE+AE,
=AF+CF+BE+AE
=AB+AC
=12+18
=30.
故选D.
∵EF ∥ BC
∴∠OCB=∠OCF,∠OBC=∠OBE
又BO、CO分别是∠BAC和∠ACB的角平分线
∴∠OCF=∠FCO,∠OBC=∠OBE
∴OF=CF,OE=BE
∴△AEF的周长=AF+OF+OE+AE,
=AF+CF+BE+AE
=AB+AC
=12+18
=30.
故选D.