Symmetrical and Non-Symmetrical Shapes, Lines, Cardinal Points for Primary 4

Class: Primary Four
Term: Third Term
Week: 8
Age: 9 years
Duration: 45 minutes
Subject: General Mathematics
Curriculum Theme: Geometry
Focal competence: Identifying differences between 2-D and 3-D shapes and distinguishing between open and closed shapes
Skills:

• identify symmetrical plane shapes
• locate line(s) of symmetry of objects in the environment
• distinguish between horizontal and vertical lines

Previous Lesson: Addition, subtraction, multiplication and division of capacities in litres
Topic: Plane Shapes
Subject Matter: Symmetrical and non-symmetrical plane shapes, horizontal/vertical lines and cardinal points

Specific Objectives

By the end of the lesson, pupils/students should be able to:

Cognitive Domain

• Identify symmetrical plane shapes.
• Distinguish between horizontal and vertical lines.
• Locate the four cardinal points (North, East, South, West).

Affective Domain

• Appreciate the importance of symmetry in everyday objects.
• Show interest in identifying different types of lines and directions.

Psychomotor Domain

• Locate line(s) of symmetry on given plane shapes.
• Draw horizontal and vertical lines accurately.
• Point to the four cardinal points in the classroom or environment.

Social Domain

• Collaborate with peers to classify shapes and identify lines of symmetry.

Reference Materials

The following resources were used in planning this lesson:

• 2025 Revised 9 Years Basic Education Curriculum
• Relevant State Unified Scheme of Work
• Primary Mathematics for Nigerian Schools, Book 4
• The HeadTeacher Scheme of work

Instructional Materials

The teacher will teach this lesson with the aid of:

• Various cut-out plane shapes (square, rectangle, triangle, circle, rhombus, trapezium, parallelogram, kite)
• Charts showing symmetrical and non-symmetrical shapes
• Charts illustrating horizontal and vertical lines
• A model of the four cardinal points (e.g., a compass rose drawing)
• Digital lacers (optional, for interactive display)
• Whiteboard/Blackboard and markers/chalk

Rationale for the Lesson

Understanding symmetrical and non-symmetrical shapes helps pupils appreciate patterns and balance in their environment. Differentiating between horizontal and vertical lines is fundamental for describing positions and directions. Learning cardinal points provides essential navigational skills and a framework for understanding geography and spatial relationships.

Prerequisite/Previous Knowledge

Pupils should have a basic understanding of different plane shapes (e.g., square, circle, triangle) and be able to identify them.

Lesson Content/Board Summary

Symmetrical and Non-Symmetrical Plane Shapes, Horizontal/Vertical Lines and Cardinal Points

Symmetrical Plane Shapes

A plane shape is symmetrical if it can be folded along a line so that both halves match exactly. This fold line is called the line of symmetry.

Examples of symmetrical plane shapes and their lines of symmetry:

1. Square: Has four lines of symmetry (two through opposite midpoints of sides, two through opposite vertices).
2. Rectangle: Has two lines of symmetry (through the midpoints of opposite sides).
3. Equilateral Triangle: Has three lines of symmetry (from each vertex to the midpoint of the opposite side).
4. Isosceles Triangle: Has one line of symmetry (from the vertex between equal sides to the midpoint of the base).
5. Rhombus: Has two lines of symmetry (along its diagonals).
6. Trapezium: An isosceles trapezium has one line of symmetry. A general trapezium has none.
7. Parallelogram: Has no line of symmetry.
8. Kite: Has one line of symmetry (along its longer diagonal).
9. Circle: Has an infinite number of lines of symmetry (any line passing through its centre).

Non-Symmetrical Plane Shapes

A plane shape is non-symmetrical if it cannot be folded along any line to make both halves match exactly.

Examples of non-symmetrical plane shapes include a general parallelogram, a scalene triangle, and an irregular quadrilateral.

Horizontal and Vertical Lines

Lines can be described by their direction.

1. Horizontal Lines: These are lines that run straight across, from left to right or right to left, like the horizon. They are flat.
2. Vertical Lines: These are lines that run straight up and down, like a wall or a standing pole. They are upright.

Differences between horizontal and vertical lines:

1. Horizontal lines go side-to-side, while vertical lines go up-and-down.
2. Horizontal lines are parallel to the ground, while vertical lines are perpendicular to the ground.

Cardinal Points

The four main directions are called cardinal points. They help us to locate places and give directions.

The four cardinal points are:

1. North (N)
2. East (E)
3. South (S)
4. West (W)

We can locate these points by knowing that if you face North, East is to your right, West is to your left, and South is behind you.

Teaching Methods/Instructional Techniques

Discussion, Demonstration, Guided Practice, Question and Answer, Explanation, Observation, Practical Activity, Group Work

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Activating prior knowledge

Teacher’s Activity: The teacher greets the pupils and asks them to name some plane shapes they know (e.g., square, circle, triangle). The teacher then asks if they notice any special features about these shapes.

Pupils’ Activity: Pupils respond by naming shapes and sharing their observations.

Learning Point: Recall of plane shapes

Step 2: Introduction to Symmetrical Shapes and Lines of Symmetry

Time: 8 minutes

Teaching Skill: Demonstration/Explanation

Teacher’s Activity: The teacher displays various cut-out plane shapes (e.g., square, rectangle, circle). The teacher folds a square in half to show that both sides match perfectly, introducing the term “symmetrical” and “line of symmetry”. The teacher repeats with other symmetrical shapes and then shows a non-symmetrical shape (e.g., a scalene triangle) that cannot be folded to match.

Pupils’ Activity: Pupils observe the teacher’s demonstration and listen to the explanation.

Learning Point: Concept of symmetry

Step 3: Identifying and Locating Lines of Symmetry

Time: 7 minutes

Teaching Skill: Guided Practice

Teacher’s Activity: The teacher distributes different symmetrical plane shapes to groups of pupils. The teacher guides them to fold the shapes to find their lines of symmetry and mark them with a pencil. The teacher provides examples like a square having four lines of symmetry and a rectangle having two.

Pupils’ Activity: Pupils work in groups to fold shapes and identify/mark lines of symmetry.

Learning Point: Locating lines of symmetry

Step 4: Distinguishing Horizontal and Vertical Lines

Time: 7 minutes

Teaching Skill: Explanation/Observation

Teacher’s Activity: The teacher draws a straight line across the board (horizontal) and another line straight up and down (vertical). The teacher explains the difference using examples from the classroom environment (e.g., the top edge of the board is horizontal, the side edge of the door is vertical). Pupils are asked to identify other horizontal and vertical lines around them.

Pupils’ Activity: Pupils observe the lines drawn and identify horizontal and vertical lines in the classroom.

Learning Point: Horizontal and vertical lines

Step 5: Introduction to Cardinal Points

Time: 6 minutes

Teaching Skill: Demonstration/Explanation

Teacher’s Activity: The teacher displays a chart or model of the four cardinal points (North, East, South, West). The teacher explains that these are the main directions and demonstrates how to locate them, perhaps by pointing North and then showing East, South, and West relative to North.

Pupils’ Activity: Pupils observe the chart and the teacher’s demonstration of cardinal points.

Learning Point: The four cardinal points

Step 6: Locating Cardinal Points in the Environment

Time: 5 minutes

Teaching Skill: Practical Application

Teacher’s Activity: The teacher asks pupils to stand up and face a particular direction (e.g., the front of the classroom). The teacher then guides them to identify North, East, South, and West within the classroom or school environment, asking them to point to each direction.

Pupils’ Activity: Pupils stand, face directions, and point to the cardinal points as guided by the teacher.

Learning Point: Practical cardinal point location

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. What is a symmetrical shape?
2. Draw a square and show its lines of symmetry.
3. Give two differences between a horizontal line and a vertical line.
4. Name the four cardinal points.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Understanding of key concepts

Step 8: Note-Taking

Time: 4 minutes

Teaching Skill: Guided Writing

Teacher’s Activity: The teacher guides pupils/students to copy the essential Board Summary notes on symmetrical/non-symmetrical shapes, horizontal/vertical lines, and cardinal points into their notebooks.

Pupils’ Activity: Pupils/students copy the notes carefully into their notebooks.

Learning Point: Recording lesson content

Step 9: Conclusion

Time: 3 minutes

Teaching Skill: Consolidation

Teacher’s Activity: The teacher briefly summarizes the lesson by reiterating the importance of symmetry, understanding different line types, and knowing cardinal points for daily life and future learning. The teacher encourages pupils to look for these concepts in their surroundings.

Pupils’ Activity: Pupils listen attentively and ask any final questions.

Learning Point: Reinforcement of concepts

Continuous Assessment/Further Study

Type: Homework

Instruction: Answer the following questions in your notebook:

1. Draw a rectangle and show its lines of symmetry.
2. Draw one horizontal line and one vertical line.
3. If you face the rising sun (East), what direction is to your left?
4. List three objects in your home that are symmetrical.
5. Which of these shapes is non-symmetrical: a circle, a scalene triangle, or an equilateral triangle?

Lesson Keywords

• Symmetry – When a shape can be divided into two identical halves.
• Line of Symmetry – The imaginary line along which a symmetrical shape can be folded.
• Horizontal – Running straight across, from side to side.
• Vertical – Running straight up and down.
• Cardinal Points – The four main directions: North, East, South, West.

Differentiation

For weaker learners, provide pre-folded shapes to trace the lines of symmetry and give simpler examples for identifying horizontal/vertical lines. For faster learners, challenge them to identify shapes with multiple lines of symmetry or to explain why certain shapes are non-symmetrical. Encourage them to draw more complex symmetrical patterns.

Suggested Lesson Videos

For further understanding and visual aids, teachers can search on YouTube for:
symmetrical shapes for primary 4 mathematics
horizontal and vertical lines primary school
cardinal points for kids

Teacher Guide for Using This Lesson Plan

Before the lesson, ensure you have a variety of cut-out plane shapes, some symmetrical and some non-symmetrical. Prepare charts showing examples of symmetrical shapes with their lines of symmetry, and clear illustrations of horizontal and vertical lines. A simple compass rose or a labelled diagram of cardinal points will be very helpful. During the lesson, actively engage pupils by allowing them to manipulate the shapes and identify lines in their environment. Emphasize the practical application of cardinal points. Watch out for common errors where pupils might confuse horizontal and vertical lines or struggle to find all lines of symmetry in complex shapes. Provide immediate corrective feedback and encourage peer-to-peer learning. Pupils should copy the Board Summary notes after the main teaching and evaluation to consolidate their learning.