New
New
Year 7

Understanding the centre of rotation

I can understand the minimum information required to fully describe a rotation.

New
New
Year 7

Understanding the centre of rotation

I can understand the minimum information required to fully describe a rotation.

Lesson details

Key learning points

  1. The centre of rotation can be on a vertex of the object .
  2. The centre of rotation can be lying inside the object .
  3. The centre of rotation can be lying outside the object .
  4. You need to give the centre, size and direction of rotation to fully describe a rotation .

Common misconception

The centre of rotation is always in the centre of an object.

The centre of rotation can be anywhere. If it's outside the shape, imagine it like a pole in the ground, attached to the object by a rope.

Keywords

  • Centre of rotation - The centre of rotation is the fixed point about which an object is rotated.

Finding the centre of rotation for other angles (such as 90°) is too complex a process for year 7. Note that this will be taught in later units on transformation.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
In which direction is this object being rotated?
An image in a quiz
clockwise
Correct answer: anti-clockwise
the object is not being rotated
Q2.
This arrow is currently pointing in the W (west) compass direction. If this arrow is rotated clockwise, what is the first compass direction that it passes through?
An image in a quiz
Correct answer: N (north)
E (east)
S (south)
W (west)
Q3.
Match the size an angle in degrees to its description.
Correct Answer:90°,a quarter turn

a quarter turn

Correct Answer:180°,a half turn

a half turn

Correct Answer:360°,a full turn

a full turn

Correct Answer:540°,one and a half full turns

one and a half full turns

Correct Answer:720°,two full turns

two full turns

Correct Answer:900°,two and a half turn turns

two and a half turn turns

Q4.
Sofia stands on the spot and rotates clockwise by a half turn and then rotates clockwise by a further three-quarter turn. In total, how many degrees has Sofia rotated by?
Correct Answer: 450, 450°, 450 degrees
Q5.
Sofia stands on the spot and rotates anti-clockwise by an angle between a quarter of a full turn and half of full turn. Which of these is a sensible answer for the size of Sofia's rotation?
85°
Correct answer: 115°
Correct answer: 175°
185°
295°
Q6.
Which of these is a suitable description for this rotation?
An image in a quiz
Correct answer: Rotated anti-clockwise by 50°.
Rotated clockwise by 50°.
Rotated anti-clockwise by 135°.
Rotated clockwise by 135°.
Rotated anti-clockwise by 180°.

6 Questions

Q1.
Which of these is the centre of rotation for this rotation?
An image in a quiz
(1, 5)
Correct answer: (3, 5)
(5, 3)
(3, 7)
(1, 9)
Q2.
Which of the following complete the full and accurate description of this anti-clockwise rotation?
An image in a quiz
centre of rotation of (3, 8)
centre of rotation of (8, 7)
Correct answer: centre of rotation of (8, 3)
Correct answer: 90° rotation
270° rotation
Q3.
Which of the following complete the full and accurate description of this clockwise rotation?
An image in a quiz
Correct answer: centre of rotation of (6, 7)
centre of rotation of (7, 6)
90° rotation
180° rotation
Correct answer: 270° rotation
Q4.
Which of the following complete the full and accurate description of this clockwise rotation?
An image in a quiz
centre of rotation of (4, 6)
Correct answer: centre of rotation of (7, 5)
centre of rotation of (10, 4)
Correct answer: 180° rotation
360° rotation
Q5.
An object is rotated by 180°. A pair of corresponding vertices on the object and image are joined with a line segment. Find the coordinates of the centre of rotation.
An image in a quiz
Correct Answer: (9, 7), (9,7)
Q6.
Which of the following complete the full and accurate description of this rotation?
An image in a quiz
180° clockwise
Correct answer: 270° anti-clockwise
centre of rotation of (11, 12)
Correct answer: centre of rotation of (14, 5)
centre of rotation of (7, 2)