设 AD=CD=a,DE=CF=x
∵ C=B=60°
∴ AB=AD=CD=a,BC=2a
∴ AE=DF=a-x
连接BF
∴ ∠ABF+∠BFD=360°-120°×2=120°
∴ ∠PBF+∠PFB=(∠ABF+∠BFD)/2=60°
∴ ∠BPF=180°-60°=120°
设 AD=CD=a,DE=CF=x
∵ C=B=60°
∴ AB=AD=CD=a,BC=2a
∴ AE=DF=a-x
连接BF
∴ ∠ABF+∠BFD=360°-120°×2=120°
∴ ∠PBF+∠PFB=(∠ABF+∠BFD)/2=60°
∴ ∠BPF=180°-60°=120°