Proportions and Similar Figures
11-7
Write the lengths of the corresponding sides in a proportion for each pair of
similar figures.
The lengths of the corresponding sides of similar figures are in proportion.
ABCDWXYZ
Study this example.
What is the length of GF?
Write a proportion.
9 24 18 m Use the cross-products rule.
216 18 m
216 18 18 m 18 Apply the Division Property of Equality.
12 m
The length of GFis 12 cm.
m
24
9
18
GF
RQ
EG
PR
2
3
2
3
2
3
2
3
2
3
6 3
9 3
2
3
6 3
9 3
2
3
6
9
2
3
6
9
AD
WZ
CD
YZ
BC
XY
AB
WX
Similar figures have the same shape and
their corresponding angles are congruent.
Z 9 Y
W^9
3 3
X
D 6 C
A^6
2 2
B
R Q
24 cm
30 cm
E P
G m
9 cm 18 cm
15 cm
F
A
B 9 cm
12 cm
15 cm
C
R
S6 cm
8 cm
10 cm
T
20 yd
P
S
Q R
8 yd
12 yd
16 yd
15 yd
W
Z
X Y
6 yd
9 yd
12 yd
C 16 cm D
F E
8 cm
6 cm 3 cm
S T
V U
20 in.
E
F J
10 in.
15 in.
24 in.
G
H
12 in.
18 in.
EFGPQR
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