连接OA,
∵∠ABC和∠ACB的平分线交于点O
∴OA是∠BAC的平分线
做OH⊥AB,∵OD⊥AC
∴OH=OD
∴S△AEF=S△AOE+S△AOF
=1/2OH×AE+1/2OD×AF
=1/2OD(AE+AF)
=1/2×1×7
=7/2