Concept 3 of 8Foundation
Watch on YouTubeVideoRotational symmetry
A shape has rotational symmetry if rotating it (less than a full 360° turn) makes it look exactly the same.
Order of rotation = how many times it matches during one full turn.
- Square: order 4 (matches every 90°)
- Equilateral triangle: order 3 (every 120°)
- Rectangle: order 2 (every 180°)
- Regular pentagon: order 5
- Circle: order infinity
Angle of rotation = 360° ÷ order.
Example
A recycling symbol (3 arrows chasing) has rotational order 3. Rotate 120°, same picture.
💡 Tip:A shape with 'order 1' doesn't really have rotational symmetry (only trivial 360° rotation).
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5 questions to check what you just read.
0 / 5
- Q1.Rotational order of a square:
- Q2.Rotational order of equilateral triangle:
- Q3.Rotational order of rectangle (non-square):
- Q4.Angle of rotation for order 6:
- Q5.Circle's rotational order: