Class 6 Maths – Chapter: Symmetry
1. Introduction
Symmetry is when a figure can be divided into two identical parts such that one part is the mirror image of the other.
- The line along which the figure is divided is called the line of symmetry.
2. Types of Symmetry
- Line Symmetry (Reflection Symmetry)
- A figure has line symmetry if it can be folded along a line and both halves match perfectly.
- Examples: Square, Rectangle, Circle, Equilateral Triangle
- Rotational Symmetry
- A figure has rotational symmetry if it looks the same after rotation by less than 360°.
- Order of rotation: Number of times it looks the same in one full rotation
- Examples: Pentagon (order 5), Star (order 5), Circle (infinite)
- Point Symmetry (Central Symmetry)
- A figure has point symmetry if every part has a matching part opposite to a central point.
- Example: Letter “S”, “Z”
3. Properties of Symmetry
- Line of symmetry divides the figure into two equal parts.
- Number of lines of symmetry varies by shape:
- Square → 4
- Rectangle → 2
- Circle → Infinite
- Equilateral triangle → 3
- Isosceles triangle → 1
4. Examples
- Line Symmetry:
- Fold a rectangle → Two halves match
- Fold an equilateral triangle → 3 lines of symmetry
- Rotational Symmetry:
- Square → Rotate 90°, 180°, 270° → Looks same → Order 4
5. Practice Questions (50 Mixed)
Part A – MCQs – 15 Questions
- A square has how many lines of symmetry?
- An equilateral triangle has how many lines of symmetry?
- Which of these has rotational symmetry of order 5? Circle, Pentagon, Rectangle, Triangle
- Which figure has infinite lines of symmetry?
- A rectangle has how many lines of symmetry?
- Letter “S” has what type of symmetry?
- Letter “Z” has what type of symmetry?
- Line symmetry is also called?
- What is the order of rotational symmetry for a circle?
- Which letter has line symmetry but not point symmetry?
- Which shape has point symmetry but no line symmetry?
- A regular pentagon has how many lines of symmetry?
- A star has rotational symmetry of order?
- Mirror divides a figure into?
- Line of symmetry passes through?
Part B – Fill in the Blanks – 10 Questions
- Line of symmetry divides a figure into ___ identical parts
- Circle has ___ lines of symmetry
- Square has ___ lines of symmetry
- Rotational symmetry means the figure looks ___ after rotation
- Order of rotational symmetry of equilateral triangle = ___
- Letter “O” has ___ lines of symmetry
- Letter “H” has ___ lines of symmetry
- Point symmetry is also called ___ symmetry
- Rectangle has ___ lines of symmetry
- Letter “T” has ___ line of symmetry
Part C – True/False – 5 Questions
- A rectangle has 4 lines of symmetry (False)
- Circle has infinite rotational symmetry (True)
- Letter “N” has point symmetry (True)
- Rotational symmetry is only for circular figures (False)
- Equilateral triangle has 3 lines of symmetry (True)
Part D – Match the Following – 5 Questions
| Column A | Column B |
|---|
| 31. Square | a) 4 lines of symmetry |
| 32. Rectangle | b) 2 lines of symmetry |
| 33. Circle | c) Infinite lines of symmetry |
| 34. Equilateral triangle | d) 3 lines of symmetry |
| 35. Pentagon | e) 5 lines of symmetry |
Part E – Short Answer / Problem Solving – 15 Questions
- Draw a square and mark all lines of symmetry
- Draw an equilateral triangle and mark lines of symmetry
- Draw letter “H” and show lines of symmetry
- Draw letter “S” and show point symmetry
- Draw a rectangle and mark lines of symmetry
- Draw letter “O” and mark lines of symmetry
- Draw a regular pentagon and mark lines of symmetry
- Draw letter “T” and mark line of symmetry
- Draw letter “Z” and show point symmetry
- Find the order of rotational symmetry of a square
- Find the order of rotational symmetry of an equilateral triangle
- Find the order of rotational symmetry of a regular hexagon
- Identify if letter “X” has line and point symmetry
- Draw a star and find order of rotational symmetry
- Draw letter “N” and show point symmetry
Answers – Class 6 Maths: Symmetry
Part A – MCQs (Answers)
- 4
- 3
- Pentagon
- Circle
- 2
- Point symmetry
- Point symmetry
- Reflection symmetry
- Infinite
- Letter “H”
- Letter “S”
- 5
- 5
- Two identical halves
- Through vertex, midpoint, or center depending on figure
Part B – Fill in the Blanks (Answers)
- Two
- Infinite
- 4
- Same
- 3
- Infinite
- 2
- Central symmetry
- 2
- 1
Part C – True/False (Answers)
- False
- True
- True
- False
- True
Part D – Match the Following (Answers)
| Column A | Column B |
|---|
| 31. Square | a) 4 lines of symmetry |
| 32. Rectangle | b) 2 lines of symmetry |
| 33. Circle | c) Infinite lines of symmetry |
| 34. Equilateral triangle | d) 3 lines of symmetry |
| 35. Pentagon | e) 5 lines of symmetry |
Part E – Short Answer / Problem Solving (Answers)
- Square: Draw square → 2 diagonals + vertical + horizontal lines → 4 lines of symmetry
- Equilateral Triangle: Draw triangle → 3 lines from vertices to opposite sides’ midpoints → 3 lines of symmetry
- Letter “H”: Draw vertical line → symmetrical on both sides → 1 line of symmetry
- Letter “S”: Point symmetry about center → every part matches opposite side
- Rectangle: Draw vertical and horizontal lines → 2 lines of symmetry
- Letter “O”: Circle → infinite lines of symmetry
- Regular Pentagon: Draw lines from each vertex to opposite side midpoint → 5 lines of symmetry
- Letter “T”: Draw vertical line through center → 1 line of symmetry
- Letter “Z”: Rotated 180° → point symmetry, no line symmetry
- Order of rotational symmetry – square: 4
- Order of rotational symmetry – equilateral triangle: 3
- Order of rotational symmetry – regular hexagon: 6
- Letter “X”: 2 lines of symmetry (diagonals) + point symmetry
- Star: Rotate 72° → looks same → Order = 5
- Letter “N”: Point symmetry about center, no line symmetry