 # Chapter 7: Triangles

Some of the most important triangles Class 9 questions i.e chapter 7 are given here. These chapter 7 class 9 maths questions cover several short answer type questions, long answer type questions and HOTS questions that are crucial for CBSE class 9 exams. Here, some of the important triangles questions class 9 from NCERT are also included.

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## Triangles Important Questions For Class 9 (Chapter 7)

These class 9 triangles questions are categorized into short answer type questions and long answer type questions. These questions cover various concepts which will help class 9 students to develop problem-solving skills for the exam.

1. Two adjacent angles on a straight line are in a ratio 5:4. Find the measure of each one of these angles. (Answer: 100 ° and 80 °degree).

2. Prove that bisectors of two adjacent supplementary angle include a right angle.

3. If two straight lines are perpendicular to the same line, prove that they are parallel to each other.

4. The angles of the triangle are in the ratio 2:3:7. Find the measure of each angle of the triangle. (Solution: 30°, 45° and 105°)

5. In triangle ABC ,  A – ∠B = 33 degree and B – C = 180 degree.Find the measure of each angle of the triangle. Answer: (A = 88° and B = 55° and C = 37°).

6. Of the three angles of the triangle, one is twice the smallest and another one is thrice the smallest. Find the angles(Answer: 60°, 90°, 30°)

7. If each of a triangle is less than the sum of the other two, show that the triangle is acute-angled.

8. The sum of two angles of a triangle is 116° and their difference is 24. Find the measure of each angle of the triangle. (Answer: 46°, 70 °, 64°).

9. Two straight lines AB and CD cut each other at O. if angle BOD = 63° then find angle BOC. (Answer: 117°).

10. Two complementary angles are such that twice the measure of the one is equal to three times the measure of the other. The larger of the two measures is. (Answer 54°).

### NCERT Questions for Class 9 Chapter 7 – Triangles     