17.[2023新高考I,18 ]如图,在正四棱柱-|||--(A)_(1)(B)_(1)(C)_(1)(D)_(1) 中, =2, (A)_(1)=4. 点-|||-A2,B2,C2,D2分别在棱AA1,BB1,CC1,-|||-DD1上, (A)_(2)=1, (B)_(2)=D(D)_(2)=2 _(2)=3.-|||-(1)证明: _(2)(C)_(2)ykparallel (A)_(2)(D)_(2);-|||-(2)点P在棱BB1上,当二面角 -(A)_(2)(C)_(2)^--|||-D2为150°时,求B 2P.-|||-C1 B1-|||-D11 A-|||-P-|||-B2-|||-D2-|||-C A B-|||-D A