如图,在△ABC与△ABD中,BC=BD,∠ABC=∠ABD.点E为BC中点,点F为BD中点,连接AE,AF.求证:AE=AF.
证明:∵BC=BD,点E为BC中点,点F为BD中点,
∴BE=BF,
∵在△ABE和△ABF中,
AB=AB∠A