Answer:
1) A
2) A
3) D
4) B
5) D
Explanation:
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FACTS TO KNOW BEFORE SOLVING :-
If any 2 parallel lines are cut by a transversal line , then :-
- its corresponding angles on same side [a pair of an interior angle and it's corresponding exterior angle (but not its adjacent exterior angle)] are equal.
- its alternate interior angles are equal.
- its alternate exterior angles are equal.
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Q1)
According to the figure on the right side of the question paper ,
- ∠2 & ∠8 are interior angles on the same side
- ∠2 = ∠7 (∵ Alternate interior angles are equal)
So,
∠7 + ∠8 = 180°
⇒ ∠2 + ∠8 = 180° (∵ ∠2 = ∠7)
Hence , we can conclude that interior angles of same side are supplementary angles. So the correct option is A.
Q2)
According to the figure on the question paper ,
- ∠5 & ∠3 are exterior angles on the same side
- ∠1 = ∠5 (∵ Corresponding angles are equal)
So ,
∠1 + ∠3 = 180°
⇒ ∠5 + ∠3 = 180° (∵ ∠1 = ∠5)
Hence , we can conclude that exterior angles on the same side are supplementary angles. So , the correct option is A.
Q3)
According to the figure , (∠2 , ∠7) & (∠1 , ∠8) are alternate interior angles. But as (∠1 , ∠8) is there as an option , so the correct option is D.
Q4)
According to the figure , m∠1 = 129°.
Also , ∠1 & ∠7 are interior angles on the same side.
⇒ They are supplementary angles.
⇒ ∠1 + ∠7 = 180°
⇒ ∠7 = 180° - 129° = 51°
So , the correct option is B.
Q5)
According to the figure , m∠2 = 3x - 10 and m∠6 = 2x + 20
Also , ∠2 = ∠6 (∵ Corresponding angles are equal)
⇒ 3x - 10 = 2x + 20
⇒ 3x - 2x = 20 + 10
⇒ x = 30
So , ∠2 = 3×30 - 10 = 80° = ∠6 (∵ Corresponding angles are equal)
Hence , the correct option is D.