1 )
A B C D
2
6 AB EF DC
BC GH AD
A
B
C
D
3 1
l2
l 1 55 , 2 65 3
A 50 B 55 C 60 D 65
4 50
A 50 B 100 C 80 D 65
5 1ABCD
28 ABC
22 AC
A14 B 12 C 10 D 8
1 2
6
7 68
A20 B 30 C 40 D 10
8 2 ABCD
A ABCD BACBD
CABD DCABCAD
9 3 ABC E D F AB BC CA DE CA
DF BA
AEDF
90BAC AEDF
AD BAC AEDF
AD BC AB AC AEDF
10 ABCD 2 EAB EFGB
AFC S
AS=2 BS=4 CS=2.4 DSBE
11 ABCD,AB
=14cm,BC
=16cm, _____cm.
3
A
G
E D
H
C
F
B
2
3
1
3
