6. Lines and Angles Class 9 Mathematics NCERT Exemplar Solutions (CBSE)

Chapter 6: Lines and Angles – Class 9 Mathematics NCERT Exemplar Solutions (CBSE Board)

Chapter 6: Lines and Angles

EXERCISE 6.1

Write the correct answer in each of the following:
1. In Fig. 6.1, if AB∥CD∥EF, PQ∥RS, ∠RQD = 25° and ∠CQP = 60°, then ∠QRS is equal to  Photo
(A) 85° (B) 135°
(C) 145° (D) 110°
2. If one angle of a triangle is equal to the sum of the other two angles, then the triangle is
(A) an isosceles triangle
(B) an obtuse triangle
(C) an equilateral triangle
(D) a right triangle
3. An exterior angle of a triangle is 105° and its two interior opposite angles are equal. Each of these equal angles is
   (A) 3712°             (B) 5212°                (C) 7212°        (D) 75°
4. The angles of a triangle are in the ratio 5 : 3 : 7. The triangle is
(A) an acute angled triangle (B) an obtuse angled triangle
(C) a right triangle (D) an isosceles triangle
5. If one of the angles of a triangle is 130°, then the angle between the bisectors of the other two angles can be
(A) 50° (B) 65° (C) 145° (D) 155°
6. In Fig. 6.2, POQ is a line. The value of x is
(A) 20° (B) 25° (C) 30° (D) 35°
                       Fig. 6.2
7. In Fig. 6.3, if OP∥RS, ∠OPQ = 110° and ∠QRS = 130°, then ∠ PQR is equal to
(A) 40° (B) 50° (C) 60° (D) 70°
                    Fig. 6.3
8. Angles of a triangle are in the ratio 2 : 4 : 3. The smallest angle of the triangle is
(A) 60° (B) 40° (C) 80° (D) 20

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Posted 4 months ago