TRƯỜNG THCS HỒNG
TRƯỜNG THCS HỒNG
BÀNG
BÀNG
HÂN HOAN CHÀO ĐÓN
HÂN HOAN CHÀO ĐÓN

QUÝ THẦY CÔ
Và

CÁC EM HỌC SINH THÂN MẾN
Giáo Viên: ĐẶNG KIỆN TRUNG


∆α

 !"#$%&
 !"#$%&
!'()*+, ./0#1!.2
-34-5%/6!7-3$8!9



3cm
5
c
m


C


$%J
$%J


KL
M
!5N-KOB
KP QI RS
; T = <U # <V
H S W A
RX Y = <U  
Z @[ \] ?
^$<V_
` ?  
a T  $
I# A  Qb EC
C

A#Y
#$$IB#$:CC
c de QV

*V
nhọn
nhọn
Cạnh
Cạnh
đối
đốilà
là
Cạnh
Cạnh
kề
kềlà
là
B
B
Q
Q




Q
Q

g
g
g
g
g
g
g
g
g
g
g
g
g
g
?

$ =

Q
$ =
Q

$ =

?

 =
?
Q
 =

g
g
g
g
g
g
g
g
g
g
g
g
?

$ =

Q
$ =
Q

$ =

?

 =
?
Q
 =
Q


QbB
?v  k[ | Y  
}|YR[
Qv    R? | Y
?}|Y?
R[


5Urd:B
~;Urd;erdB
/3l!3mB
:n@RI^oB
G!I@we;x^B
Kz@•B
i ; x ^ T? _ P S QA
;€I?B


5Urd:B
+% &' , !   / 01 23 4 5
"26'7&(&87
9:;< &= 7 9:
;
 " % .$> ?<  
@ABC/D,<E&(<F
DGH<IJKL<HF



:

sin.
≈=°=
=


5UrdGB
~;Urd;erdB
/3l!3mB
:n@RI^oB
G!I@we;x^B
K=@•B
$

#
EC
C
:
C
C

3skSQA;Vq•QAB!URS;TH
SW#IP<VZ@[QIB#⊥#$$
EC
C
A#$:CC


G I Ợ {GI I VDẢ G
M
 ∆  

1!/3*‚6l-
1!/3*‚6l-
-3J
-3J
-3#-3
-3#-3
Kz-3*{5ƒ#34
Kz-3*{5ƒ#34
 
 !!
" !
# !!


2∆WXQ
$"#



?

Q
Q?$?y ??$
Q$y QQ$


L