Mathematics · Class 7
Lines and Angles
Complementary, supplementary, adjacent, and vertically opposite angles.
4 sections15–25 min read6 MCQs · 2 examples
Chapter Overview
Study pairs of angles — complementary, supplementary, adjacent, linear pair, vertically opposite — and angles formed when a transversal cuts parallel lines.
Angle Pairs
- Complementary: sum 90°
- Supplementary: sum 180°
- Linear pair: adjacent + supplementary on a line
- Vertically opposite angles are equal
Transversal on Parallel Lines
- Corresponding angles are equal
- Alternate interior angles are equal
- Co-interior angles sum to 180°
Types of Angles
- Acute < 90°; Right = 90°; Obtuse > 90°
- Reflex: between 180° and 360°
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
Example 1: Complementary
One angle is 35°. Find its complement.
- 1Complement = 90° − 35°
Answer
55°
Example 2: Transversal
Two parallel lines cut by transversal. If one corresponding angle is 72°, find its pair.
- 1Corresponding angles equal
Answer
72°
Key Points to Remember
- ✓ Linear pair always sums to 180°
- ✓ Vertically opposite angles equal
- ✓ Parallel line theorems need parallel condition
Exam Tips
- • State angle relationship before calculating
- • Draw diagram for transversal problems
Practice MCQs — Lines and Angles
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 6Score: 0/0
Supplement of 110° is: