内容正文:
课时7综合法求空间角与距离
一
母
B
0
A
D
B
C
D
B
C
B
/
BC
r=号h
96=号×36M
h=8
OL
9
b
OIN
5
58
WP
boy
W‘8FZ个='aFb'aY-O8F
AC
D
DC
BD
AM∥DC
制
AM
BC
DC
BC
∠BCD
ABC-ABC
2|DC=5|BDl=5|BC=22
IBG =IDC+BD
△BDC
cos∠aCD=oal_Vi0
AM BC
1而
B
4
ABCD
E F
AC
BD
AB=23
CD=4
EF⊥AB
EF
CD
30°
45°
60°
90°
G
AD
GF
GE
E F
AC
BD
GF
GE
△ABD
△ACD
GFI∥AB
GE/ICD
GE--CD=2
EF
CD
EF
GE
EF⊥AB
2
EF⊥GF
△GEF
∠GFE=90°
sin∠GEF=
GF 3
GE
2
∠GEF=60°
EF
CD
60°
G
E
B
ABC-ABC
23
AB=6
AB=2
AA
1-2
BC,BC
D,D
AD=3V3,4D=3
5665分2x-
ABC-ABC
Pa=3++x=号
h=
45
3
A.D
M,N
A
C
AM=x
B
D
B
话=ya4=+
DN=AD-AM-MN=23-x
00=Dx-4-25-+
BCC B
旺62u+-3--94
4V3
AA
3
tan∠AAD=
AM
=1
AM
ABC-ABC
P-ABC
B
B
AA
1
PA
PAAB
PA
AB 3
VP-ABC
1
52
VABC-AC=
VP-ABC =18
P-ABC
VP-ABC
27
27
3
d
1,
d=2v5
32
2
0
PO⊥
A0=2V3
PA
P
tan∠PAO=
P0=1
A0
/
P
D
C
B
A
C
B
D
A
C
E
B
0
ABCD-ABCD
M
ABB A
AM=元AB+(1-2)AA
MC
AAB
岛
[
9
AM=元AB+(1-2)A4
A
CB AC
BM
CB⊥
AAB
CM
AAB
∠C,MB,
CB
CM
CB=AC=AB=V2CB
CM⊥AB
CM-
5c8-6
2
9cGMs8
2CB.v6
C
3
CM
B
AAB
[]
D
M
P-ABCD
PA⊥
PA=AC=2
BC=1,4B=3
P
AD⊥PB
ADI∥
PBC
D
AD⊥DC
A-CP-D
√42
AD
7
B
PA⊥
ABCD
ADC
ABCD
PA⊥AD
AD⊥PB
PB∩PA=PPB,PAc
PAB
AD⊥
PAB
ABC
PAB
AD⊥AB
BC2+AB2=AC2
BC⊥AB
AD//BC
AD丈
PBC
BCc
PBC
AD//
PBC
DE⊥AC
E
EEF⊥CPF
DF
B
PA⊥
ABCD
PAC⊥
ABCD
PAC∩
ABCD=AC
DE⊥
PAC
EF⊥CP
CP⊥
DEF
∠DFE
A-CP-D
V42
sin∠DFE=
1
tan∠DFE=√6
AD⊥DC
AD=x
CD=4-x2
DE=xV4-x
c4
△EFC
2
2
xv4-x2
EF=
4-x2
tanm∠DFE=,2,=V6
x=V3
2W2
4-x2
2W2
AD=3
C
A
B
C
B
C
B
C
M
B
M
M
D
W
段D
C
B
!
!
C
B
C
B
A
B
-3
/
感谢观看
THANKS