TOPIC: POLYGONS AND LINES OF SYMMETRY
A: TEACHING AND LEARNING MATERIALS
- Polygon charts.
- Cut-out plane shapes.
- Rulers.
- Mirrors.
- Foldable paper.
- Shape flashcards.
- Pupils’ exercise books and pencils.
B: REFERENCE MATERIALS
- Scheme of work.
- Recommended Mathematics textbook for Primary 6.
- Online educational resources.
C: PREVIOUS KNOWLEDGE
The pupils can identify common plane shapes such as triangles, squares and rectangles and can describe their sides and angles.
D: PERFORMANCE OBJECTIVES
By the end of the lesson, pupils should be able to:
- Explain the meaning of a polygon.
- Name polygons according to their number of sides.
- Identify common polygons.
- State simple properties of polygons.
- Explain the meaning of symmetry.
- Identify lines of symmetry.
- Draw lines of symmetry on simple shapes.
- Identify some common three-dimensional shapes.
E: CONTENT
Meaning of a Polygon
A polygon is a closed plane shape made up of straight sides.
Examples:
🔺 Triangle
⬜ Square
▭ Rectangle
Types of Polygons
| Number of Sides | Name |
|---|---|
| 3 | Triangle |
| 4 | Quadrilateral |
| 5 | Pentagon |
| 6 | Hexagon |
| 7 | Heptagon |
| 8 | Octagon |
Triangle
A triangle has:
- 3 sides
- 3 angles
- 3 vertices
Quadrilateral
A quadrilateral has four sides.
Examples include:
- square
- rectangle
- parallelogram
- trapezium
Meaning of Symmetry
A shape is symmetrical if it can be divided into two matching halves.
The line that divides it into matching halves is called a line of symmetry.
Examples of Lines of Symmetry
A square has 4 lines of symmetry.
A rectangle has 2 lines of symmetry.
An equilateral triangle has 3 lines of symmetry.
Three-Dimensional Shapes
Common solid shapes include:
- cube 🧊
- cuboid 📦
- cylinder
- cone
- sphere ⚽
F: LESSON PRESENTATION
F1: Teachers’ Activities
- Shows pupils different polygon shapes.
- Explains the meaning of a polygon.
- Names polygons according to their sides.
- Discusses simple properties of polygons.
- Introduces symmetry by folding paper.
- Demonstrates lines of symmetry.
- Introduces common solid shapes.
- Gives identification exercises.
F2: Pupils’ Activities
- Identify polygons.
- Count the sides of polygons.
- Name polygons correctly.
- State simple properties of shapes.
- Fold paper to show symmetry.
- Draw lines of symmetry.
- Identify common solid shapes.
- Complete shape exercises.
G: CONCLUSION
The teacher revises the names of polygons and explains again that a line of symmetry divides a shape into two matching halves.
The teacher corrects pupils where necessary and encourages them to identify shapes in their environment.
H: EVALUATION GUIDE
Pupils should be able to answer the following questions:
- What is a polygon?
- How many sides does a pentagon have?
- Name a polygon with six sides.
- Name a polygon with eight sides.
- What is a line of symmetry?
- How many lines of symmetry does a square have?
- How many lines of symmetry does a rectangle have?
- Name three solid shapes.