Study Guide and Intervention (continued) - MathnMind

11-6
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Study Guide and Intervention
Similar Triangles
Similar Triangles RST is similar to XYZ. The angles of the
two triangles have equal measure. They are called corresponding
angles. The sides opposite the corresponding angles are called
corresponding sides.
Similar Triangles
If two triangles are similar, then the
measures of their corresponding sides
ABC DEF
are proportional and the measures of
their corresponding angles are equal.
AB BC AC
DE EF DF
Determine whether
the pair of triangles is similar.
Justify your answer.
R
Example 1 Example 2
75
S
45
T
X
50
89 Y
Z
Since corresponding angles do not have
the equal measures, the triangles are
not similar.
Exercises
© Glencoe/McGraw-Hill 673 Glencoe Algebra 1
A
Z X
30
S
60
60
Y
30
R T
B D
Determine whether the pair
of triangles is similar. Justify your answer.
F
90
G
I
45 H 45
E
45
J
The measure of G 180° (90° 45°) 45°.
The measure of I 180° (45° 45°) 90°.
Since corresponding angles have equal
measures, EFG HIJ.
Determine whether each pair of triangles is similar. Justify your answer.
1. 2. 3.
30
4. 5. 6.
30
120
40
30
30
30
110
60
45
60
80
90
45
45
55
20
120
30
115
E
C
F
Lesson 11-6