Mathematics · Class 7
Symmetry
Rotational symmetry and order of symmetry in regular polygons.
4 sections15–25 min read6 MCQs · 2 examples
Chapter Overview
Class 7 symmetry covers line symmetry, rotational symmetry, and symmetry in regular polygons — connecting art, rangoli, and architectural patterns across India.
Rotational Symmetry
- Figure looks same after rotation about a point
- Order of rotational symmetry: number of times it matches in 360°
- Square has rotational symmetry of order 4
Line Symmetry Review
- Regular n-gon has n lines of symmetry
- Circle: infinite lines and rotational symmetry of infinite order
Combined Symmetry
Many rangoli and mandala designs combine both line and rotational symmetry for visual balance.
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
Example 1: Rotational Order
Find order of rotational symmetry of equilateral triangle.
- 1Matches at 120°, 240°, 360°
Answer
Order 3
Example 2: Line Symmetry
How many lines of symmetry does a regular hexagon have?
- 1Regular n-gon has n lines
Answer
6 lines
Key Points to Remember
- ✓ Centre of rotation for rotational symmetry
- ✓ Angle of rotation = 360°/order
- ✓ Line symmetry ≠ rotational always
Exam Tips
- • Mark centre of rotation clearly
- • Distinguish line vs rotational in questions
Practice MCQs — Symmetry
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 6Score: 0/0
Order of rotational symmetry of square: