∵ABCD－A1B1C1D1是正方体,∴ABCD、AA1B1B、AA1D1D是三个全等的正方形,∴A1B＝A1D＝BD＝√2AB＝2√2,∴△A1BD的面积＝（1/2）BD^2sin60°＝2√3.∵ABCD－A1B1C1D1是正方体,∴AB⊥平面AA1D1D,∴B－A1D1D的体积＝（1/3...