7.
а)
N ∈(BCC1B1)∪(A1B1C1D1) - две плоскости.
B ∈(ABCD)∪(ABB1A1)∪(BCC1B1) - три плоскости.
K ∈(ABB1A1)∪(ADD1A1) - две плоскости.
б)
BC ∈(ABCD)∪(BCC1B1)
NP ∈(BCC!B1)
LF ∈(ABB1A1)
в)
MK ∩ (BB1C1) = L
NQ ∩ (ABC) = Q
NQ ∩ (A1B1C1) = N
MK ∩ (ABC) = F
г)
(AA1B1) ∩ (BB1C1 = BB1
(MNP) ∩ (AA1B1) = MK.
(MNP) ∩ (ABC) = FQ