A、B在水平面上
F A=G A,F B=G B
又∵ p A =
F A
s A =
G A
s A , p B =
F B
s B =
G B
s B
∴G A=P AS A,G B=P BS B
∴
G A
G B =
p A S A
p B S B =
p A
p B ×
S A
S B =
1
2 ×
4
1 =
2
1
故选B.
A、B在水平面上
F A=G A,F B=G B
又∵ p A =
F A
s A =
G A
s A , p B =
F B
s B =
G B
s B
∴G A=P AS A,G B=P BS B
∴
G A
G B =
p A S A
p B S B =
p A
p B ×
S A
S B =
1
2 ×
4
1 =
2
1
故选B.