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Assertion and Reason Questions for Class 9 Maths Chapter 6 Lines and Angles, , Directions: In the following questions, a statement of assertion (A) is followed by a, statement of reason (R). Mark the correct choice as:, , (a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation, of assertion (A)., , (b) Both assertion (A) and reason (R) are true but reason (R) is not the correct, explanation of assertion (A)., , (C) Assertion (A) is true but reason (R) is false., , (d) Assertion (A) is false but reason (R) is true., , Q.1. Assertion : Sum of the pair of angles 120° and 60° is supplementary., Reason: Two angles, the sum of whose measures is 180°, are called supplementary, , angles., , Answer, , Answer: (a), , Q.2. Assertion: The angles of a triangle are in the ratio 2:3: 4. The largest angle of the, triangle is 80°., , Reason: The sum of all the interior angles of a triangle is 180°, , Answer, , Answer: (a), , Q.3. Assertion : If angles ‘a’ and ‘b’ form a linear pair of angles and a = 40°, then b =, 150°., , Reason: Sum of linear pair of angles is always 180°., , Answer, , Answer: (d)

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Q.4. Assertion: In the given figure, AOB is a straight line. If Z AOC = (3x + 10)’ and, ZBOC (4x - 26)°, then ZBOC = 86°, , Reason: The sum of angles that are formed on a straight line is equal to 180°, , , , Answer, , Answer: (a), , Q.5. Assertion : If two interior angles on the same side of a transversal intersecting, two parallel lines are in the ratio 5:4, then the greater of the two angles is 100°, Reason: If a transversal intersects two parallel lines, then the sum of the interior, , angles on the same side of the transversal is 180°, , Answer, , Answer: (a), , Q.6. Assertion : An angle is 14° more than its complementary angle, then angle is 52°., Reason: Two angles are said to be supplementary if their sum of measure of angles is, , 180°, , Answer, , Answer: (b), , Q.7. Assertion : Supplement of angle is one fourth of itself. The measure of the angle is, 144°, Reason: Two angles are said to be supplementary if their sum of measure of angles is, , 180°

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Answer, , Answer: (a), , Q,8. Assertion: The value of x from the adjoining figure, if 2 || m is 15°., Reason: If two parallel lines are intersected by a transversal, then each pair of, , corresponding angles so formed is equal., , (120° - x), 5x, , Answer, , Answer: (b), , Q.9. Assertion : If two internal opposite angles of a triangle are equal and external, angle is given to be 110°, then each of the equal internal angle is 55°., , Reason: A triangle with one of its angle 90°, is called a right triangle, , Answer, , Answer: (b), , Q.10. Assertion : A triangle can have two obtuse angles., , Reason: The sum of all the interior angles of a triangle is 180°, , Answer, , Answer: (d)

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Q.11. Assertion : The angles of a triangle are in the ration 3:5:7. The triangle is acuteangled, , Reason: The sum of angles that are formed on a straight line is equal to 180°., , Answer, , Answer: (b)