NCERT MCQ CLASS 9 CHAPTER 6 | LINES AND ANGLES |

NCERT MCQ FOR LINES AND ANGLES

Question 1.

In ΔABC, ∠A = 50° and the external bisectors of ∠B and ∠C meet at O as shown in figure. The measure of ∠BOC is

(a) 40°
(b) 65°
(c) 115°
(d) 140°

Answer: (b) 65°

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Question 2.

In figure the value of x is

(a) 120°
(b) 130°
(c) 110°
(d) 100°

Answer: (b) 130°

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Question 3.

An exterior angle of a triangle is 80° and the interior opposite angles are in the ratio 1 : 3, measure of interior opposite angles are
(a) 30°, 90°
(b) 40°, 120°
(c) 20°, 60°
(d) 30°, 60°

Answer: (c) 20°, 60°

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Question 4.

In ΔABC, the bisectors of ∠ABC and ∠BCA intersect each other at O. The measure of ∠BOC is
(a) 90° + ∠A
(b) 90° + ∠A2
(c) 180 – ∠A
(d) 90° – ∠A2

Answer: (b) 90° + ∠A2

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Question 5.

In figure if ∠A + ∠B + ∠C + ∠D + ∠E + ∠F = k right angles, then find value of k.

(а) 2
(b) 3
(c) 4
(d) 5

Answer: (c) 4

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Question 6.

In the given figure, the measure of ∠ABC is

(a) 80°
(b) 20°
(c) 100°
(d) 60°

Answer: (a) 80°

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Question 7.

The angle of a triangle are in the ratio 5 : 3 : 7, the triangle is
(а) an acute-angled triangle
(b) an obtuse angled triangle
(c) an right angled triangle
(d) an isosceles triangle.

Answer: (а) an acute-angled triangle

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Question 8.

In figure l₁ || l₂, the value of x is

(a) 80°
(b) 100°
(c) 110°
(d) 70°

Answer: (a) 80°

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Question 9.

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: (d) a right triangle

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Question 10.

One of the angles of a triangle is 75°. If the difference of other two is 35°, then the largest angle of other two angles has a measure
(a) 80°
(b) 75°
(c) 70°
(d) 135°

Answer: (c) 70°

Question 11 .

 If AB = x + 3, BC = 2x and AC = 4x – 5, then for what value of ‘x’, B lies on AC?

a) 2

b) 3

c) 5

d) 8

Answer: (d) 8

Question 12 .

 In the given figure, if AOB is a line then the measure of ∠BOC, ∠COD and ∠DOA respectively are:

a) 36^o, 54^o, 90^o

b) 36^o, 90^o, 54^o

c) 90^o, 36^o, 54^o

d) 90^o, 54^o, 36^o

 Answer: (a) 36^o, 54^o, 90^o

Question 13 .

In the figure, if x, y and z are exterior angles of ΔABC then x + y + z is:

a) 90^o

b) 180^o

c) 270^o

d) 360^o

Answer: (d) 360^o

Question 14 .

In the given figure, PQ || RS and ∠ACS = 127°, ∠BAC is:

a) 50^o
b) 53^o
c) 77^o
d) 107^o

Answer c) 77^o

Question 15.

In figure, AB || ED, the value of x is:

a) 26^o
b) 36^o
c) 54^o
d) 62^o

Answer a) 26^o

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