Download 7. Find the scale factor of ⁄DEFG to ⁄HJKL. 8. Find the length of DE

8.3
Examples on
pp. 473–475
SIMILAR POLYGONS
EXAMPLE The two parallelograms shown are similar because their corresponding
angles are congruent and the lengths of their corresponding sides are proportional.
XY
3
WX
ZY
WZ
= = = = QR
4
PQ
SR
PS
W
X
110ⴗ 70ⴗ
m™P = m™R = m™W = m™Y = 110°
Z
m™Q = m™S = m™X = m™Z = 70°
q
P
110ⴗ
70ⴗ
9
12
Y
12
S
R
16
3
The scale factor of ⁄WXYZ to ⁄PQRS is .
4
In Exercises 7–9, ⁄DEFG ~ ⁄HJKL.
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D
7. Find the scale factor of ⁄DEFG to ⁄HJKL.
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8. Find the length of DE and the measure of ™F.
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9. Find the ratio of the perimeter of ⁄HJKL to the perimeter of ⁄DEFG.
8.4
Examples on
pp. 480–482
SIMILAR TRIANGLES
EXAMPLE Because two angles of ¤ABC
are congruent to two angles of ¤DEF,
¤ABC ~ ¤DEF by the Angle-Angle (AA)
Similarity Postulate.
E
B
55ⴗ
55ⴗ
A
C
D
F
Determine whether the triangles can be proved similar or not. Explain why
or why not. If they are similar, write a similarity statement.
10.
11.
V
S
F
28ⴗ
K
12.
L
P
R
64ⴗ 75ⴗ
q
38ⴗ
104ⴗ
X
W
U
8.5
75ⴗ
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H
S
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Examples on
pp. 488–491
PROVING TRIANGLES ARE SIMILAR
EXAMPLES Three sides of ¤JKL are
proportional to three sides of ¤MNP, so
¤JKL ~ ¤MNP by the Side-Side-Side
(SSS) Similarity Theorem.
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K
M
Chapter 8 Geometry English-Spanish Reviews
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18
12
24
16
J
38A
33ⴗ
J
104ⴗ 48ⴗ
33ⴗ
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