证明:
∵ABC-A1B1C1是三棱柱
∴AA1//BB1//CC1
∵AA1⊥BC
∴CC1⊥BC
∵A1B⊥BB1
∴A1B⊥CC1
∵ BC∈平面A1BC,A1B∈平面A1BC,BC∩A1B=B
∴CC1⊥平面A1BC
∵A1C∈平面A1BC
∴A1C⊥CC1
证明:
∵ABC-A1B1C1是三棱柱
∴AA1//BB1//CC1
∵AA1⊥BC
∴CC1⊥BC
∵A1B⊥BB1
∴A1B⊥CC1
∵ BC∈平面A1BC,A1B∈平面A1BC,BC∩A1B=B
∴CC1⊥平面A1BC
∵A1C∈平面A1BC
∴A1C⊥CC1