Grade 9 · Math · Unit 9 of 11
Line & Rotation Symmetry
Fold lines, turns and the order of symmetry.
What your child practises
Practises lines of symmetry and rotation symmetry (order and angle of rotation) in polygons, letters and designs.
Manitoba Curriculum learning outcome: 9.SS.5 · line and rotation symmetry
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
What is the smallest turn angle for a regular pentagon?
- 60°
- 108°
- 72°
72°
Hint: 360° ÷ 5.
Question 2
How many lines of symmetry does an equilateral triangle have?
- 3
- 6
- 1
3
Hint: One from each vertex to the opposite side.
Question 3
A parallelogram that is not a rectangle has rotation symmetry of order…
- 0
- 4
- 2
2
Hint: A half-turn (180°) fits it on itself.
Question 4
Which letter has a line of symmetry but no rotation symmetry (in a plain font)?
- N
- Z
- T
T
Hint: T folds along a vertical line but is upside down after a half-turn.
Question 5
What is the smallest turn angle for a regular octagon?
- 60°
- 45°
- 90°
45°
Hint: 360° ÷ 8.
Question 6
A shape has order 5 rotation symmetry and 5 lines of symmetry. Which shape could it be?
- an isosceles triangle
- a rectangle
- a regular pentagon
a regular pentagon
Hint: A regular n-gon has n lines and order n.