Lesson 2.3: Geometry – Patterns & Symmetry | SEA Mathematics | My Carib Academy
SEA 2025-2028 Framework Aligned

🔷 Lesson 2.3: Geometry – Patterns & Symmetry

Master repeating & growing geometrical patterns and line symmetry in shapes, letters & numerals. This lesson covers SEA Mathematics Objectives 117-125 from the Geometry Strand.

60 Minutes
Module 2: Geometry
Objectives 117-125
2 Videos
Lesson Progress 0%

Previous Lesson

Did you complete Lesson 2.2? Review Polygons, Quadrilaterals & Triangles →

Learning Objectives

By the end of this lesson, you will be able to:

  • Recognize and extend repeating geometrical patterns (Objectives 117-118)
  • Recognize and extend growing geometrical patterns (Objectives 119-121)
  • Identify line symmetry in 2D shapes (Objectives 122-123)
  • Identify line symmetry in letters and numerals (Objectives 124-125)
  • Draw lines of symmetry on shapes

SEA Tip

Pattern and symmetry questions appear in Section I and II of the SEA Math paper. These are visual questions that test your observation skills! (SEA Framework Page 23-24)

Watch: Geometrical Patterns

Start by watching this video to learn about repeating and growing geometrical patterns. Take notes as you watch! 📝

Geometrical Patterns – Mathematics Video Lesson

Quick Check

Did you understand the video? Review the notes below before continuing! ✅

Repeating & Growing Geometrical Patterns

A pattern is a sequence that follows a rule. Let’s learn the two main types of geometrical patterns!

Two Types of Patterns

  • Repeating Pattern: The same sequence repeats over and over (e.g., â–³ â—‹ â–¡ â–³ â—‹ â–¡…)
  • Growing Pattern: The pattern increases or changes in a predictable way (e.g., 1 square, 2 squares, 3 squares…)

📊 Repeating Pattern Examples:

Pattern A

Circle → Square → Triangle
Repeats every 3 shapes

Pattern B

Teal → Orange → Teal
Repeats every 2 shapes

📊 Growing Pattern Examples:

Growing Pattern A

Each shape gets taller
+20 height each time

Growing Pattern B

Each circle gets bigger
+10 radius each time

📋 How to Find the Pattern Rule:

Step-by-Step Method
  1. Look at the first 3-4 items in the pattern
  2. Identify what changes (shape, color, size, position)
  3. Describe the rule in words
  4. Test your rule on the next item
  5. Extend the pattern using your rule

Common Mistake

Don’t just look at one feature! Check shape, color, size AND position to find the complete pattern rule.

Watch: Line Symmetry

Now watch this video to learn about line symmetry in shapes, letters and numerals. Pay attention! 🎯

Line Symmetry in Shapes, Letters & Numerals – Mathematics Video Lesson

Line Symmetry

A shape has line symmetry if you can fold it in half and both sides match perfectly. The fold line is called the line of symmetry!

What is Line Symmetry?

  • Line of Symmetry: A line that divides a shape into two matching halves
  • Reflection Symmetry: One half is a mirror image of the other
  • Test: If you fold along the line, both halves match exactly

📊 Symmetry in Shapes:

Square

4 lines of symmetry

Rectangle

2 lines of symmetry

Equilateral Triangle

3 lines of symmetry

Circle

Infinite lines of symmetry

📊 Symmetry in Letters:

A

Vertical Symmetry

A, H, I, M, O, T, U, V, W, X, Y

B

Horizontal Symmetry

B, C, D, E, H, I, K, O, X

H

Both Symmetries

H, I, O, X

📊 Symmetry in Numerals:

0

0

2 lines of symmetry

8

8

2 lines of symmetry

3

3

1 horizontal line

1

1, 2, 4, 5, 6, 7, 9

No lines of symmetry

Memory Trick

Symmetry = Mirror – If you put a mirror on the line, you should see the complete shape!

Quick Quiz

Test your understanding! Select an answer for each question. 🔷

6 Questions
12 Minutes
70% to Pass

1. What type of pattern is: â–³ â—‹ â–¡ â–³ â—‹ â–¡ â–³ â—‹ â–¡ …?

2. How many lines of symmetry does a square have?

3. Which letter has BOTH vertical and horizontal symmetry?

4. Which numeral has 2 lines of symmetry?

5. What is a line of symmetry?

6. Which shape has NO lines of symmetry?

0/6

Lesson Complete!

Great job finishing Lesson 2.3! You’re mastering geometry patterns and symmetry for the SEA exam! 🎉

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