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).

Starter quiz

6 Questions

Q1.
In which direction is this object being rotated?
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?
E (east)
S (south)
W (west)
Q3.
Match the size an angle in degrees to its description.

a quarter turn

a half turn

a full turn

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

one and a half 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°
185°
295°
Q6.
Which of these is a suitable description for this rotation?
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°.

Exit quiz

6 Questions

Q1.
Which of these is the centre of rotation for this rotation?
(1, 5)
(5, 3)
(3, 7)
(1, 9)
Q2.
Which of the following complete the full and accurate description of this anti-clockwise rotation?
centre of rotation of (3, 8)
centre of rotation of (8, 7)
Correct answer: centre of rotation of (8, 3)
270° rotation
Q3.
Which of the following complete the full and accurate description of this clockwise rotation?
Correct answer: centre of rotation of (6, 7)
centre of rotation of (7, 6)
90° rotation
180° rotation
Q4.
Which of the following complete the full and accurate description of this clockwise rotation?
centre of rotation of (4, 6)
Correct answer: centre of rotation of (7, 5)
centre of rotation of (10, 4)