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Class 5

Chapter 10: Symmetrical Designs

A figure has rotational symmetry if it looks the same after a turn. The order of symmetry counts how many times it matches in one full turn.

Learning outcomes

  • Use lines and rotational symmetry
  • Design rangoli using symmetry rules

Activities

  • Make a symmetric rangoli on paper

Worked examples

Read through these first, then try the practice below.

  1. Example 1 — Order of rotational symmetry

    An equilateral triangle looks the same every 120° turn. What is its order of rotational symmetry?

    Solution: It matches 3 times in a full turn, so order = 3.

  2. Example 2 — Square symmetry

    What is the order of rotational symmetry of a square?

    Solution: A square matches every 90°, so order = 4.

Self-do practice

Question 1 of 3 · Score 0/0

What is the order of rotational symmetry of a regular hexagon?

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