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ÔN THI TỐT NGHIỆP THPTQG PHẦN HÌNH HỌC KHÔNG GIAN

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P/#S2P0
S",L)*! !"*/A-.P$<'4)*$"H)*0@.P$.M$N"H)*J,)*J,)*
 [0L+`#5J#^P#S2P
*",L)*! !"*/A-"-/<'4)*$"H)*!"E,)"-1
 [5(*9P
 [0L+`#5J#^
d

( )
mp a
'
'd

$$G
d

 [0L+?#S2P$$
( ) ( )
,a b
VN'
d

'd

a
α β
φ
a
b
u
M
d
'd
M
M
D
H
M
d
'd
S
A
B

C
H
O
A
B C
D
S
O
H

9/)""DN>1
O6)")*"T-
5;2Nb;2:< U&@.P$<-*/ !<>1!D!"V)
<'4)*!-,$+W)*0I/$V.!;-<-*/ !< U
A@I=
 ;2:+#S&^?#+>&7+#S&^
G++&7
 +&^*;2:G#S++&7
&O-/"?)"!"DN<>1$"'4)**MN
* Hnh chp tam gic đu:;2#+:
.S ABC
B
 +
AB C
#+:
 +#S&^+#+>
S

 :
SO


 c?&^#S+
·
·
·
SAO SBO SCO= =

 c?#S&^#S+
·
SHO

 "d
 
2 1 3
, ,
3 3 2
AB
AO AH OH AH AH= = =

 [Y;2#+:0+G'():
+ '():+#S+#+:
+ '():;2#+:&^&7+
* Hnh chp t gic đu;2#+:
.S ABCD

 +
AB CD
;
 +#S&^+#+>
S


 :
SO

 c?&^#S+
·
·
·
·
SAO SBO SCO SDO= = =

 c?#S&^#S+
·
SHO

e
A
B

X !6)"'4)*-,?)""DN
-?)"!"DN!D.P$!Y)"=Z)012)**D!
0I/< U
:*;25(
&^G+
K7C[;2
.S ABC
&^
( )
SA ABC^
;:

SA

=?)"!"DN!D.P$.M$=Z)012)**D!
0I/.M$< U
:*;2:*
#+'#S&^
G+
K7C[;2
.S ABCD
#S&^
( )
SAB
G#S+
( )
ABCD
;:*;2
:*
SABD

!?)"!"DN!D"-/.M$=Z)012)**D!
0I/< U
:*;2
*#S&^RG+
K7C[;2
.S ABCD
#S&^
( )
SAB

( )

SAD
R
G#S+
( )
ABCD
;:

SA

C?)"!"DN<>1
:*;2P
%C>#*+
K7C[;2'+:
.S ABCD

>##S2P+J#*
=;
AB CD
;
SO

\"Q7!""]/-:/#)
"Q$7!"^"]/!"DN
1
.
3
V B h=
:B
6)"#S+


:h
:*0%2
3"Q$7!"^"]/&_)*$+[
.V B h=
:B
6)"#S+

:h
:*0%2
[Y[fU':g
&^
h

6
F
E


-
-i
i i

-

i
-i
i

&





F

i
-
i

i

-


5"Q$7!""?)""PN!"A)"B$
. .V abc=
Þ
"Q$7!"^"]/&BNN"'`)*
3
V a=
9aJ]$"Q$7!"
. ' ' '
.
' ' '
. .
S A B C
S ABC
V
SA SB SC
V SA SB SC

=
?)"!"DN![$bcbbc
( )
' '
3
h
V B B BB= + +
jG
, ',B B h
()"+:

ccdefg
"7C[Cho hnh chp
.S ABC
c đy là tam gic vuông tại
·
0
, 30 ,B BAC SA AC a= = =

SA
vuông gc với
( )
mp ABC
.Tính th! tích kh#i chp
.S ABC
và khoảng cch
c@/*/L/$" ^"L,
"J"0%2
.S ABC


k
( )

.
1
. . 1
3
S ABC ABC
V S SA
D
=
k
( )
 2SA a=
k;#
ABC
S
D
l

ABCD

B

0
0
0
0
.sin30
sin30

2
3
cos30
.cos30
2
a
BC
B C AC
AC
AB
a
AB AC
AC
ì
ì
ï
ï
ï
ï
= =
=
ï
ï
ï
ï
ï ï
Û
í í
ï ï
ï ï

=
= =
ï ï
ï ï
ï
î
ï
î
( )

2
1 1 3 3
. . . 3
2 2 2 2 8
ABC
a a a
S AB BC
D
Þ = = =
m
F


-
W
n
n


k

( ) ( )
2 , 3

( )
2 3
.
1 3 3
1 .
3 8 24
S ABC
a a
V aị = ì =
/
( )
4
"0L+`
A

( )
mp SBC

k
( ) ( ) ( )

.
.
3.
1
, . , 5
3

S ABC
S ABC SBC
SBC
V
V d A SBC S d A SBC
S
D
D
ộ ự ộ ự
= ị =
ờ ỳ ờ ỳ
ở ỷ ở ỷ
k;#
SBCD
l

( )
BC AB
B C mp SAB BC SB SBC
BC SA

ù
^
ù
ị ^ ị ^ ị D

ù
^
ù



B

2 2
2 2 2 2 2 2
1 1 1 3 3
. . . . .
2 2 2 2 2
SBC
a a
S B C BS AC AB SA AB a a
D
ổ ử ổ ử
ữ ữ
ỗ ỗ
ữ ữ
ỗ ỗ
ị = = - + = - +
ữ ữ
ỗ ỗ
ữ ữ
ỗ ỗ
ữ ữ
ỗ ỗ
ố ứ ố ứ
( )

2
1 7 7
6

2 2 2 8
a a a
= ì ì =
k
( ) ( )
4 , 6

( )
5
( )
3
2
3 8 21
, 3
24 7
7
a a
d A SBC
a
ộ ự
ị = ì ì =
ờ ỳ
ở ỷ

"7C[3Cho hnh chp
.S ABCD
c y
AB CD
l hnh ch nht c
, 2AB a BC a= =

. Hai
( )
mp SAB
v
( )
mp SAD
c'ng vuụng gc vi m(t
ph)ng y, cnh
SC
hp vi y mt gc
0
60
. Tớnh th! tớch kh#i chp
.S ABCD
theo
a
.
c@/*/L/$" ^"L,

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( ) ( ) ( )
( ) ( )
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ù
^
ù
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ù
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ù
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;*
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^
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mp ABCD

AC

( )
ã
ã
0
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ờ ỳ
ờ ỳ
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( )

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1
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o
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a
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/

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.S ABC
c
2BC a=
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AB C
l tam gic vuụng ti
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l
tam gic vuụng cõn ti
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v nm trong m(t ph)ng vuụng gc vi m(t y.
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( )
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.
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>
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ã
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( )
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KI AC mp ABC mp SAC mp ABC SK I
SK AC mp SAC

ù
^ =
ù
ù
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ù

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ớ ờ ỳ
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ở ỷ
ù
^ è
ù
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( )

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1
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V S SI
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=
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I

ã ã
( )

0
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2
SI
SKI SI IK SKI BC a
IK
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S
D
l
( )
2

2 2 2
1 1 1
. . . . . . 2
2 2 2
ABC
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D
= = - = -
( )
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2
2
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2
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( )
3
2
.
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3 3

S ABC
a
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. ' ' 'AB C A B C
c y
AB C
l tam gic u cnh bng
a
.
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xu#ng
( )
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l trung i!m ca
AB
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bờn
( )
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to vi y mt gc bng
45
o
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tr ny
c@/*/L/$" ^"L,
cb
, ,H M I
VNJ#*+

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, ,AB AC AM


( )

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V B h S A H
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= =
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:^
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2 2
. 3 3
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B C a
S
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l

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^g

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IH AC
MB AC

ù
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( )
'
' '
AC A H
AC A HI AC A I
AC IH


ù
^
ù
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ù
^
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( ) ( )
ã
ã
0
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' ( ' ')
AB C ACC A AC
AC IH ABC ACC A ABC A IH
AC A I ACC A

ù
ầ =
ù
ù
ộ ự
ù
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ở ỷ
ù
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ù
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'A HID

H

( )


0
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tan45 ' .tan45 3
2 4
A H a
A H IH IH MB
HI
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,,

i
-
i


i

-


p



 
( ) ( )
2 , 3

( )
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. ' ' '
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a a a
VÞ = =

"7C[Cho hnh lăng trụ đng
. ' ' 'AB C A B C
c đy
AB C
là tam gic vuông tại
·
0

, , 60A AC a ACB= =
. Đường chéo
'B C
của m(t bên
( )
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tạo với
m(t ph)ng
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một gc
0
30
. Tính th! tích của kh#i lăng trụ theo
a
.
c@/*/L/$" ^"L,
 
( )
AB AC
AB ACC A
AB AA
ì
ï
^
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í
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^
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AC
¢
;
*
BC
¢
^
( )ACC A
¢ ¢

`?
BC
¢
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( )ACC A
¢ ¢

·
0
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¢
=
.
 #+
AB C


0
.tan60 3AB AC a= =
.
 #+
'ABC

0
.cot30 3. 3 3AC AB a a
¢
= = =
.
 #+
'ACC
:
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.
 j@J"fU
3
1 1
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2 2
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/(
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c cạnh đy
2a

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bằng
0
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c@/*/L/$" ^"L,
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.S ABCD
 cb
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( )
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M

J#
CD

 
·
0
( )
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( ) ( )
CD SM SCD

CD OM ABCD SMO
CD SCD ABCD
ì
ï
^ Ì
ï
ï
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í
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= Ç
ï
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
SMOD

O

·
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SO
SMO
OM
=
·
( )
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0
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2
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2 2
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2
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3 3
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a
V a aÞ = =
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;2
.S ABC
+
AB C
#+>
( )
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?
( )
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( )
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&7
0
30
cb
M
J#*
SC
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.S ABM
q
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D
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2
36
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a
V VÞ = =
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
a
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AB CD
cb
, ,M N P
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, ,SB BC CD
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CMNP

:cb
H
J#*

AD
;
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( )
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( )
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D
=
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a a a
= =
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s
B

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+
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&;^
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SA ABCD

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1

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D
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b>#
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^
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2
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.
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AI AO
AD a
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ù
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ù
ù
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ù
ù
ù


ù
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ù



ù
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ù



ù
ố ứ
ù

2 2

2 2 2 2
3 6
3 3
a a
AB a AI BI AIB
ổ ử ổ ử
ữ ữ
ỗ ỗ
ữ ữ
ỗ ỗ
= = + = + ị D
ữ ữ
ỗ ỗ
ữ ữ
ỗ ỗ
ữ ữ
ỗ ỗ
ố ứ ố ứ
p
2 3
.
1 2 2
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a a a
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fU#+
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( )
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0
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#+
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C

ã
0
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^
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b>#*
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'A ABC
q
a


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B
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^
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G
^
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ã
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p
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A
p
E

i
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c
A




( )

'
1 1
. . ' . . . ' 1
3 6
A ABC ABC
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D
= =

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l
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
G

·
0
' 60B BG =
^?#+:
'BB a=

( )
 
3
; ' 2

2 2
a
a
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 ;#
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l
S
2AB x=

ABCD

C

·
0
60BAC =
^
g?#+:G
B C

, 3
2
AB
AC x BC xÞ = = =
6
G
b>#
ABCD

3 3
2 4
a
B N BGÞ = =


BNCD

C

2 2 2
B N NC BC= +
( )

2 2 2
2 2
3
9 9 3
2 13
3 3
16 4 52
3 3
2 13
2 13
a
AC
a x a a
x x x
a
BC

ì
ï
ï
=
ï
ï
ï
ï
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í
ï
ï
=
ï
ï
ï
ï
î
 
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2 , 3

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'
1 3 3 3 3 9
1 . . .
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2 13 2 13
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a a a a
VÞ = =
c@/0%2F-+#+\-tt9 CF+
:-#S&^/F-N2G#S+/-en
n
"J"0%2
F-
:
,a
e
n
n
-
 
A

c

c@/\0%fU-i-ii+#+:&7&^&7
Wa
;/*i^/-RGJ#*-"
J"0%fU`$J"*0%2i-
:
c@/n;fU'-i-ii+#5#+t&
·
n
enACB =
 =-i*#S&^ iiG#S2P/ii#5
Wn
n


 '##+
uABC

& "5(i
 "J"*0%fU-i-ii`$J"*0%2
i-
:
c@/ph+7!"<>$"/$1UQ)J/)"Y/"m!^"]/j3kk\l
;@22<
. ' ' ' 'AB CD A B C D
&7,cb
,M N
VN
J#*
AB

CD
"0L+?P
'A C

MN

6ssb5 F
( )
2
, '
4
d MN AC =
c@/o;2

.S ABC
+
AB C
#+
( )
,B SA mp ABC^

-7
,AB a=

2AC a=
?#S2P
( )
SBC

( )
ABC
&7
0
60
"J"0%2
.S ABC
q
a

F
3
2
a
V =


c@/k;2
.S ABC
+
AB C
#+>
( )
,B SA ABC^


2AC a=

3SB a=
"J"*0%2
.S ABC

,e

F
3
2
3
a
V =
 !=Y)!D$"Q$" ^"L,! !$@/&/#1^" !q<VU
/cpvswrjxjxE yzAc[pAx{|AAx}
"$$N35C,!,+*$+-)*s!-s)"-)s\o9ks)*1U8)s0-)s
!"1U8)"$.
,h

×