KT Ch 3 H học 8



  ! "#$ %
 &  &  & '! ( )
*+,(-#./011(23
4






5

678179:.;<!=/01
(678179





>/?(@AB'C/
/011)C/



5





D

C/E@AFB(G#3
/0111)C/
H



 




I#$/0111)C/
(G#3


5


D 

% 
DJK
D
DJK
D
LJK
M
KJK

N.O
PEQ/;)
R21(234NSH/)JTSK/)P*+,(234N:.T7.R
1





/


#


5P2U:VTWOONJ1/XR
1P
AB AC
DE DC
=

AB DE
BC DC
=
/
AB DE
BE CE
=
#
AB AD

DE BE
=

DP2U:V5PN7.1B'C//01

A
U
1
AB BI
AC BC
=

AB AC
BC CI
=
/
AB BI
AC IC
=
#
AB CI
AI AC
=
LP2U:VDPN11)C/Y:.YZ(G#3:[1!J+!\E1R
1SZ OOZ /
MNP RQP∆ = ∆
#=1JJ/(]!(^
_P2U:VLWJ`7.E!( )/01NJP(X
a


5
L



N

1
ABC AEF∆ ∆
b2*+,cS



AEF ABC
∆ ∆
b2*+,cS5
/
AEF ABC∆ ∆
b2*+,cS



#
AFE ABC
∆ ∆
b2*+,cS5

5DL
HP11)C/N:.dNdd(G#31!!R
1

 
 
A B B C
AB BC
′ ′ ′ ′
′
=

 
 
 

B C
BC
′ ′ ′ ′
′
=
/
   
 
 
 
′ ′ ′ ′
′
=
MPC//'!+1!(^1\+1
P11)C/(G#3Ue1!P
5P11)C/:!/'7!(G#3:[1!P
DP11)C/e1!U(G#3:[1!P
LP*+,/!:/0111)C/(G#3e*+,(G#3/011

1)C/(XP


NPf&!MJ_(g

 !!"#$
5DJ_(P
21)C/N:!3J(@A/12P
hiYJZ7j7@F7.E!( )/01NJ
k)R
1
%&
%
J_(
hiYJZ7j7@F7.E!( )/01NJP
k)R
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
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J_(
D21)C/N/XNS/)JSK/)PEl/3N7?\( )+12/2
SH/)J:V(@A4<!1:.+2+2:[/QN3J:V(@A4
<!1:.+2+2:[N/Q3YP>/!:kC/YP5J_(

mYm
!EQ/;))5J_(
*+      ,
/.  0 1  1 
B
C

A
E
D
I
B
C
A
F
E
B
C
A
6
3
2
x
P
M
N
Q
R
a

5
L



N
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*+)
NOf7!R
 "#$)
2 !!
AN AM
NC MB
⇒ =

"3455678$

 9:7811*+0
9:7811*+

B
A
C
Q
H
P

0 !#
 )HBA ABC∆ ∆

:;<1




= 



 
AHB BAC
B chung
HBA AB C
= =
⇒ ∆ ∆
 !#
BPH AQH∆ ∆

!#;<1)






 
BPH cân tai P
AQH cân tai Q
HAQ PBH
BPH AQH
∆
∆
=
⇒ ∆ ∆

*+ *+ *+ *+
> - - -
 "6 ')

9:7811*+0

A
B
C
M
N
P

9 !#;<1 '?55
9 >+@A0 'B 
9 "6;<1 1#
9 "3455678 '=1#
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