1 ABC CDBABCD AD= A=
2 ABE DCEAE=2cmBE=1.5cm A=25 B=48
DE= cm EC= cm C= .
3 ABC DBC A=800 ABC=30
0 DCB=
1 2 3 4
4 ABC ADE
11.2.1 sss
1 1AB=ACBD=CD B=28 C=
2 2 EDF BACEC=6 BF=
3 ABEFDC ABC900ABDC
1 2 3
4 ABC C900BC40AD BAC BCD DCDB35 DAB
5 ABC ADBCCEAB DEADCE H
AEH CEB
4 5 6 8
6 AEAFABACECBF O A600 B250 EOB
A 600 B 700 C 750 D 850
7
A B C D
8 1 2 3 4ECAD ABE BDC
11.2.2 SAS
1 ABO DCO.
ABO DCO
AB=CD ( )
____________( )
____________( )
ABO DCO
2 ACB ADB.
ACB DCO
_____ ______
_______ _____
_______ _____
ABO ADB
1 (1) SAS AB=AC = ABDACE.
1 3 4
2 (3),D CB CE // AD CE=AD ED= ED //
3 ABCEFG B=68 G-E=56 C=
4 (4),ABC AD=AE BD=EC ADB= AEC=105 B=40 CAE=
5 ABC A=50 BO CO B C O BOC A.
600B. 100 0C. 1150D. 130 0
E
BA
DCFE
D
CB
A
E
D C
B
A
12
F
E
D
C
B
A
C
D
A
B
O
D
C
B
A
