BC⊥平面AA1B1B,则平面ABC⊥平面AA1B1B,判定是直棱柱
A1C与底面成45°
矩形AA1C1C是正方形,CC1=A1C1=2√2
SΔabc=2*2/2=2
V=SΔabc*AA1=2*2√2=4√2