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SAI InternationalSchool
CLASS - IX

Mathematics
CHAPTER-6: LINES AND ANGLES ANSWERS

Assessment (Subjective)-2

SUBTOPIC:Parallel Lines and a Transversal

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1. In the given figure, l || m and a transversal t cuts them. If ∠1 = 120 , find the
measure of each of the remaining marked angles.

Solution:
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It is given that ∠1 = 120
From the figure we know that ∠1 and ∠2 form a linear pair of angles
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∠1 + ∠2 = 180
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120 + ∠2 = 180
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∠2 = 180 - 120
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∠2 = 60
From the figure, we know that ∠1 and ∠3 are vertically opposite angles.
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∠1 = ∠3 = 120
From the figure, we know that ∠2 and ∠4 are vertically opposite angles
So,
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∠2 = ∠4 = 60
It is given that, l || m and ‘t’ is a transversal
So, the corresponding angles according to the figure is written as
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∠1 = ∠5 = 120
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∠2 = ∠6 = 60
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∠3 = ∠7 = 120
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∠4 = ∠8 = 60
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