(2014?江门一模)如图,四棱锥P-ABCD的底面ABCD是平行四边形,PA⊥底面ABCD,PA=3,AD=2,AB=4,∠ABC=6

2025-05-08 15:20:24
推荐回答(1个)
回答1:

(1)连接AC,
AC=

AB2+BC2?2AB?BCcos60°
=
16+4?2×4×2×
1
2
=2
3

∴PC=
AC2+PA2
=
12+9
=
21

∵PB=
AB2+PA2
=