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Class 6

Chapter 9: Symmetry

A figure has line symmetry if it can be folded along a line so the two halves match. It has rotational symmetry if it looks the same after a partial turn.

Learning outcomes

  • Identify lines and rotational symmetry
  • Create symmetric designs

Activities

  • Mirror-paint symmetric butterflies

Worked examples

Read through these first, then try the practice below.

  1. Example 1 — Lines of symmetry

    How many lines of symmetry does a regular pentagon have?

    Solution: 5 — one through each vertex.

  2. Example 2 — Order of rotation

    What is the order of rotational symmetry of a rectangle (not a square)?

    Solution: Order 2 — it looks the same after a 180° turn.

Self-do practice

Question 1 of 3 · Score 0/0

How many lines of symmetry does a regular hexagon have?

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