CBSE Class 9 Maths extra questions and answers for Chapter 6 - Lines and Angles provided here for students to revise important fundamental concepts. Practicing with these questions will help you strengthen your basics and prepare well for the exams. All these questions are provided with answers. Try to understand and solve each question appropriately. These questions are like a practice test that is best for self-assessment.

**CBSE Class 9 Maths Extra Questions for Chapter 6 - Lines and Angles****:**

**1. If two lines intersect each other then the vertically opposite angles will be _______.**

**Answer: **

If two lines intersect each other then the vertically opposite angles will be __equal__.

**2. If the angles of a triangle are in the ratio 5 : 3: 2 then the triangle is:**

**(a) An acute-angled triangle**

**(b) An obtuse-angled triangle**

**(c) An isosceles triangle**

**(d) A right triangle **

**Answer:**

(d) A right triangle

(Hint; Let the angles be 5x, 3x and 2x so that 5x + 3x + 2x = 180. Then find out the value of all three angles)

**3.Is it possible to have a triangle with two obtuse angles? Give reason to support your answer.**

**Answer:**

No, it is not possible to have a triangle with two obtuse angles. Because if the triangle will have two obtuse angles (angles greater than 90°), then the sum of all three angles of the triangle will not be equal to 180°, it will be more than 180°.

**4. How many triangles can be drawn with its three angles being 47°, 70° and 85°? Give reason for your answer.**

**Answer:**

None

Sum of given angles = 47° + 70° + 85° = 202° ≠ 180°.

Since the sum of all three angles is not equal to 180°. So, no triangle can be drawn with the given angles.

**5. A transversal intersects two parallel lines as shown in the figure given below. Then which of the following statements is correct?**

**(a) Each pair of alternate interior angles is equal.**

**(b) Each pair of corresponding angles is equal.**

**(c) Each pair of interior angles on the same side of the transversal is supplementary.**

**(d) All the above statements are equal.**

**Answer:**

(d) All the above statements are equal.

**Also Check: **

**NCERT Solutions for Class 9 Maths**

**6. What is Linear Pair Axiom?**

**Answer:**

Linear Pair Axiom is a combination of the two theorems. These are:

(i) If a ray stands on a line, then the sum of two adjacent angles so formed is 180°.

(ii) If the sum of two adjacent angles is 180°, then the non-common arms of the angles form a line.

**7. What do you mean by allied angles?**

**Answer:**

Interior angles on the same side of the transversal are referred to as consecutive interior angles or allied angles or co-interior angles.

**8. In the following figure, find the value of x.**

**Answer:**

x = 18^{o}

**9. In the following figure, OP and OQ are the bisectors of ****∠BOC and ****∠AOC. Then find ****∠POQ.**

**Answer:**

∠POQ = 90^{o}

**10. An exterior angle of a triangle is _________ than either of its interior opposite angles.**

**Answer:**

An exterior angle of a triangle is __greater__ than either of its interior opposite angles.

Students must go through the latest CBSE Syllabus for Class 9 Maths so that they can prepare according to the contents prescribed by the board.

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