Lines and Angles Class 9 MCQ with Answers

Lines and Angles Class 9 MCQ with Answers – Maths Class 9 MCQ Online Test are covered in this Article. Lines and Angles Class 9 MCQ Test contains 30 questions. Answers to MCQ on Lines and Angles Class 9 are available after clicking on the answer. MCQ Questions for Class 9 with Answers have been made for Class 9 students to help check the concept you have learnt from detailed classroom sessions and application of your knowledge.

Board CBSE
Textbook Maths (NCERT)
Class Class 9
Chapter Chapter 6 Lines and Angles
Category MCQ Questions for Class 9 Maths with Answers

Lines and Angles Class 9 MCQ with Answers

1. If three or more points lie on the same line, they are called

(a)collinear

(b)non-collinear

(c)either (a) or (b)

(d)neither (a) and (b)

Answer

Answer: (a)collinear


 

2. Two angles whose sum is 90° are called

(a)acute angle

(b)right angle

(c)supplementary angle

(d)complementary angle

Answer

Answer: (d)complementary angle


 

3.In figure which of the following angles are vertically opposite

(a)∠p and ∠s

(b) ∠s and ∠q

(c) ∠r and ∠p

(d) ∠p and ∠q

Answer

Answer: (d) ∠p and ∠q


 

4.Two parallel lines intersect at

(a)1 point

(b)2points

(c)no point

(d)4 points

Answer

Answer: (c)no point





5. If ∠MOX = 90°, and ∠NOY = 67°, then ∠MON =

(a)23°

(b)27°

(c)33°

(d)37°

Answer

Answer: (a)23°

Explanation: ∠MOX +∠NOY +∠MON = 180° [Linear pair of angles]

By putting values

90° + 67° + ∠MON = 180°

157° + ∠MON = 180°

∠MON=180° -157°

∠MON = 23°


 

6.The sum of the three angles of a triangle is

(a)180°

(b) 80°

(c) 170°

(d) 160°

Answer

Answer: (a)180°


 

7. If ∠AQP = 110° and ∠BRP = 125°, then ∠QPR is

(a)45°

(b)55°

(c)65°

(d)75°

Answer

Answer: (b)55°

Explanation: ∠AQP + ∠PQR = 180° [ Linear pair of angles]

110° + ∠PQR = 180°

∠PQR = 70°

∠PRB +∠PRQ = 180° [ Linear pair of angles]

125° + ∠PRQ = 180°

∠PRQ = 55°

Now, In triangle PQR

∠PRQ + ∠PQR + ∠QPR = 180°

55° + 70° + ∠QPR = 180°

∠QPR = 180° -125°

∠QPR=55°


 

8. If a + b + f = d + e + c, then POQ is

(a)Line

(b)Triangle

(c)either line and triangle

(d)none of these

Answer

Answer: (a)Line

Explanation: Given, a + b + f = d + e + c

We know that the angles around a point are 360° so,

a + b + f + d + e + c = 360°

2 (a + b + f) = 360°

a + b + f = 180°

Hence, POQ is a line.


 

9. A line joining two end points is called

(a)ray

(b) line segment

(c)parallel line

(d) None of these

Answer

Answer: (b) line segment


 

10. Consecutive interior angles of the transversal are

(a)∠P and ∠A

(b) ∠P and ∠C

(c) ∠S and ∠B

(d) ∠S and ∠A

Answer

Answer: (c) ∠S and ∠B


 

Lines and Angles Class 9 MCQ with Answers

11. If a transversal intersects two parallel lines, then each pair of corresponding angles are

(a)equal

(b)unequal

(c)double

(d)half

Answer

Answer: (a)equal


 

12.MN is a transversal which intersects two parallel lines PQ and RS and ∠A=70°,∠B,∠C and ∠D are interior angles, then ∠C =

(a)90°

(b)110°

(c)180°

(d)360°

Answer

Answer: (b)110°

Explanation: We know that, if a transversal intersects two parallel lines, then each pair of interior angles on the same side of the transversal is supplementary.

∠A+∠C = 180°

∠C= 180° – 70°

∠C=110°


 

13. A line with one end point is called a

(a)ray

(b)line segment

(c)either ray or line

(d)None of these

Answer

Answer: (a)ray

Explanation:


 

14. AB || CD and EF⊥ AB, ∠EGH = 55°, then what will be the value of x, y, w and z

(a)x = 90°, y = 55°, w = z = 125°

(b) x = y = 55°, w = z = 125°

(c)x = 55°, y = 45°, w = z = 125°

(d) x = 90°, y = w = z = 125°

Answer

Answer: (a)x = 90°, y = 55°, w = z = 125°

Explanation: ∠GEF =x [Corresponding angles]

x = 90°

Now,

∠EGH = 55°

w + ∠EGH = 180° [pair of interior angles on the same side of the transversal is supplementary]

w + 55° = 180°

w = 125°

Now, y = ∠EGH [Corresponding angles]

y = 55°

Now, w = z [Alternate interior angles]

z = 125°





15. In below figure, find ∠S and ∠T

(a) ∠S = 10°, ∠T = 110°

(b) ∠S = 110°, ∠T = 100°

(c) ∠S = 110°, ∠T = 10°

(d) ∠S = 120°, ∠T = 10°

Answer

Answer: (c) ∠S = 110°, ∠T = 10°

Explanation: In triangle ADC

∠ADB = ∠DAC + ∠ACD [If a side of a triangle is produced, then the exterior angle so formed is equal to the sum of the two interior opposite angles.]

∠ADB = ∠S = 15° + 95°

∠S = 110°

Now, In triangle ADB

∠S+∠T+∠ABD = 180° [Angle sum property]

110° + ∠T + 60° = 180°

∠T = 180° – 170°

∠T = 10°


 

16. AD ⊥ PQ and BC ⊥ PQ, then find value of x

(a) x = 10°

(b) x = 60°

(c) x = 70°

(d) x = 80°

Answer

Answer: (a) x = 10°

Explanation: In triangle ADC

∠ADC + ∠ACD +∠DAC = 180° [angle sum property]

80° + 90° +∠DAC = 180°

∠DAC = 180° – 170°

∠DAC = y = 10°

Now, y + ∠BAC = 90° [AD ⊥ PQ]

10° + ∠BAC = 90°

∠BAC = 90° – 10°

∠BAC = 80°

Now, In triangle ABC

∠BAC + ∠ABC + x = 180° [angle sum property]

80° + 90° + x = 180°

x = 10°


 

17: The value of a straight angle is

(a)180°

(b) 90°

(c)0°

(d)None of these

Answer

Answer: (a)180°


 

18 In the below figure, find value of x

(a) 40(1/4)°

(b) 42(4/1)°

(c) 41(1/4)°

(d) 42(1/4)°

Answer

Answer: (d) 42(1/4)°

Explanation: ∠x+8° + ∠x + ∠x – 2° + ∠x + 60° -55° = 180° [Linear pair of angles]

4∠x + 11° = 180°

4∠x = 169°

∠x = 169/4 = 42(1/4)°


 

19.If lines PT and SQ intersect at point R, such that ∠ PRQ = 60°, ∠ RTS = 50°, find ∠ RST

(a) 60°

(b) 50°

(c) 70°

(d) 80°

Answer

Answer: (c) 70°

Explanation: PT and SQ intersect at point R

∠ PRQ = ∠ SRT =60° [Vertically opposite angle]

In triangle SRT

∠ SRT +∠ RST + ∠ RTS = 180 [ Angle sum property]

60° + ∠ RST + 50° = 180°

∠ RST = 180° – 110°

∠ RST = 70°


 

Lines and Angles Class 9 MCQ with Answers

20 If one angle of triangle is equal to the sum of the other two, then the triangle is

(a) an isosceles triangle

(b) an obtuse-angled triangle

(c) an equilateral triangle

(d) a right triangle

Answer

Answer: (d) a right triangle

Explanation: The sum of interior angles of a triangle is equal to 180°. In the right triangle, one angle should be equal to 90°, and the remaining two angles are acute angles, and their sum is equal to 90°.


 

21. If lines AE and BD intersect at point C, ray CF is the angle bisector of ∠ACB and ∠AFC=∠BCF = 90°, ∠CED = 100° and ∠DCE = 50°, then

(a) x <y

(b) x = y

(c) x >y

(d) x ≠ y

Answer

Answer: (b) x = y

Explanation: Lines AE and BD intersect at point C

∠DCE = ∠ACB = 50° [Vertically opposite angle]

CF is the angle bisector of ∠ACB

So, ∠ACF = ∠BCF = 1/2×∠ACB

∠ACF = ∠BCF = 1/2×50° = 25°

Now, In triangle ACF

∠ACF+ ∠AFC + y = 180° [angle sum property]

25° + 90° + y = 180°

y = 180° – 115°

y =65° ………… (1)

Similarly, In triangle BCF

∠BCF+ ∠BFC + x = 180° [angle sum property]

25° + 90° + x = 180°

x = 180° – 115°

x =65°………………. (2)

From (1) and (2)

x =y =65°


 

22. If ratio of angles of a triangle is 3:4:5 then the value of largest angle is

(a) 75°

(b) 85°

(c) 95°

(d) 105°

Answer

Answer: (a) 75°

Explanation: Let the angles of the triangle be 3x, 4x and 5x.

Now, 3x + 4x + 5x = 180° [angle sum property]

12x = 180°

x = 180°/12

x = 15°

Now, the angles of the triangle are 3×15° = 45°

4×15° = 60°

5 ×15°= 75°


 

23. The triangle whose angles are in the ratio 7:3:5, is called

(a)an acute angled triangle

(b) an obtuse-angled triangle

(c) an equilateral triangle

(d) a right triangle

Answer

Answer: (a)an acute angled triangle

Explanation: Let the angles of the triangle be 7y, 3y and 5y.

Now, 7y + 3y + 5y = 180° [angle sum property]

15y = 180°

y = 12°

The angles of the triangle are 84°, 36°, 60°.

So, value of all angles is less than 90°, the triangle is acute angled triangle.





24. If PQ || RS, AB ⊥ PQ and ∠ ACS = 131°, find ∠BAC

(a) ∠BAC = 21°

(b) ∠BAC = 31°

(c) ∠BAC = 41°

(d) ∠BAC = 51°

Answer

Answer: (c) ∠BAC = 41°

Explanation: ∠BAC + ∠PAB = 131° [alternate interior angle]

∠BAC + 90° = 131°

∠BAC = 131°-90°

∠BAC = 41°


 

25. A reflex angle is:

(a)more than 90°

(b)less than 180°

(c)more than 180°

(d)less than 90°

Answer

Answer: (c)more than 180°


 

26. If the angles a and b are in the ratio 5: 6, then angle c is

(a) ∠c = 66°

(b) ∠c = 106°

(c)∠c = 116°

(d) ∠c = 126°

Answer

Answer: (d) ∠c = 126°

Explanation: Let the angles a and b are 5x and 6x.

∠a +∠b + 81° = 180° [linear pair of angles]

5x + 6x = 180° – 81°

11x = 99°

x = 9°

∠a = 5x = 5(9°) = 45°

∠b = 6x = 6(9°) = 54°

∠c +54° = 180° [linear pair of angles]

∠c = 180° – 54°

∠c = 126°


 

 

27. The diagonals of a square ABDC intersect at O. If ∠ABO = 61°, then ∠OAB is:

(a) 28°

(b) 29°

(c) 30°

(d) 31°

Answer

Answer: (b) 29°

Explanation: We know that diagonals of a square bisect each other at right angles.

So, ∠AOB = 90°

Now, In triangle ABO

∠AOB + ∠ABO+∠OAB = 180° [angle sum property]

90° + 61° + ∠OAB = 180°

∠OAB = 180° – 151°

∠OAB = 29°


 

28. If ratio of two supplementary angles is 2x:3x, then the angles are

(a)72°, 108°

(b)110°, 70°

(c)60°,120°

(d)100°, 80°

Answer

Answer: (a)72°, 108°

Explanation: We know that supplementary angles are those angles whose sum is 180°.

2x + 3x = 180°

5x = 180°

x = 36°

Two angles are 72° and 108°.


 

29. The value of an obtuse angle is

(a)less than 90°

(b) less than 180°

(c) less than 270°

(d) greater than 90° and less than 180°

Answer

Answer: (d) greater than 90° and less than 180°


 

30. The value of each angle of an equilateral triangle is

(a)70°

(b)65°

(c)60°

(d)55°

Answer

Answer: (c)60°

Explanation: We know that the angles of an equilateral triangle is in the ratio 1:1:1.

Let angles be x, x and x

x +x + x = 180° [angle sum property]

3x = 180°

x = 60°


 

MCQ Questions for Class 9 Maths

Frequently Asked Questions on Lines and Angles Class 9 MCQ with Answers

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Yes. There are 30 MCQ’s on this Chapter in this blog.

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