Lines and Angles — Important Questions
Karnataka Board · Class 9 · Mathematics
30 important questions from Lines and Angles for Karnataka Board Class 9 Mathematics, with answers. Includes multiple choice questions.
Interactive on Super Tutor
Studying Lines and Angles? Get the full interactive chapter.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for important questions and more.
Free trial, no card needed.
Important Questions from Lines and Angles
In triangle ABC, if ∠A = 60° and ∠B = 80°, what is ∠C?
Show answer
40°
Step 1: The sum of all angles in a triangle is always 180°. Step 2: ∠A + ∠B + ∠C = 180°. Step 3: Substitute the given values: 60° + 80° + ∠C = 180°. Step 4: 140° + ∠C = 180°. Step 5: ∠C = 180° - 140° = 40°.
If two angles are complementary and one angle is 35°, find the other angle.
Show answer
55°
Step 1: Complementary angles are two angles whose sum is 90°. Step 2: Let the unknown angle be x°. Step 3: Given angle + x° = 90°. Step 4: 35° + x° = 90°. Step 5: x° = 90° - 35° = 55°.
Lines PQ and RS intersect at O. If ∠POR : ∠ROQ = 3:2, find ∠POR.
Show answer
108°
Step 1: ∠POR and ∠ROQ form a linear pair, so they are supplementary. Step 2: ∠POR + ∠ROQ = 180°. Step 3: Given ratio ∠POR : ∠ROQ = 3:2, so let ∠POR = 3x and ∠ROQ = 2x. Step 4: 3x + 2x = 180°, so 5x = 180°. Step 5: x = 36°, therefore ∠POR = 3 × 36° = 108°.
If AB || CD and EF is a transversal, and ∠AEF = 130°, find ∠EFC (alternate interior angle).
Show answer
130°
Step 1: When parallel lines are cut by a transversal, alternate interior angles are equal. Step 2: ∠AEF and ∠EFC are alternate interior angles. Step 3: By the Alternate Interior Angles theorem, these angles are equal when lines are parallel. Step 4: Therefore, ∠EFC = ∠AEF = 130°.
+26 more questions on Lines and Angles (Karnataka Board Class 9 Mathematics)
Practise AllFrequently Asked Questions
What are the important topics in Lines and Angles for Karnataka Board Class 9 Mathematics?
How many important questions are there in Lines and Angles?
Sources & Official References
- Karnataka SSLC — kseeb.kar.nic.in
- Dept of Pre-University Education, Karnataka
- National Education Policy 2020 — education.gov.in
Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.
More resources for Lines and Angles
For serious students
Get the full Lines and Angles chapter — start free.
Quizzes, flashcards, an AI doubt solver and a study plan for Karnataka Board Class 9 Mathematics. Free to start, no card needed.