New
New
Year 7

# Rotating objects

I can rotate objects using information about centre, size and direction of rotation

New
New
Year 7

# Rotating objects

I can rotate objects using information about centre, size and direction of rotation

## Lesson details

### Key learning points

1. Tracing paper can be a helpful tool to perform a rotation.
2. The image and the object should be congruent.
3. Unless a full rotation occurs, the object and its image will not have the same orientation.

### Common misconception

After drawing an object on the tracing paper, you take the tracing paper off the table to rotate it.

This is especially dangerous if the centre of rotation wasn't drawn on the tracing paper, too. The image will lose its correct location.

### Keywords

• Clockwise - A clockwise direction is the direction in which the hands of an analogue clock travel.

• Anti-clockwise - An anti-clockwise direction is the opposite direction to which the hands of an analogue clock travel.

• Centre of rotation - The centre of rotation is the fixed point about which an object is rotated. It fixes the location of the image after it is rotated.

• Degrees - Degrees are the most common unit of measurement for angle. One whole turn is equal to 360 degrees, written 360°.

For all diagrams where vertices or the centre of rotation overlap inside the object, students need to press hard enough through the tracing paper so that they can see the mark on the paper.
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.
Match the size an angle in degrees to its description.

a quarter turn

a half turn

a three-quarter turn

a full turn

a one-and-a-half turn

a one-and-three-quarter turn

Q2.
Which of these is an accurate description for this rotation?
Correct answer: Rotated clockwise by 90°.
Rotated clockwise by 270°.
Rotated anti-clockwise by 90°.
Correct answer: Rotated anti-clockwise by 270°.
Q3.
What is the centre of rotation for this rotation?
Q4.
This object has been rotated clockwise. By how many degrees did this object rotate?
Correct Answer: 180, 180°, 180 degrees, 180degrees
Q5.
A pair of corresponding vertices on the object and image are joined with a line segment. Join a second pair of vertices to find the coordinates of the centre of rotation.
(3, 4)
(11, 8)
(7, 4)
(9, 7)
Q6.
This object has been rotated by 180°. The image overlaps its object. Find the coordinates of the centre of rotation.

## Exit quiz

### 6 Questions

Q1.
When you use tracing paper to rotate an object, which two things should you draw onto the tracing paper?
the origin
exactly two vertices of the object
both the \$\$x\$\$-axis and \$\$y\$\$-axis
Correct answer: the centre of rotation
Q2.
After which step can you remove the tracing paper in order to progress onto the next step in completing your rotation?
after drawing the object and centre of rotation on the tracing paper
after drawing the image on the paper underneath
after pushing your pencil onto the centre of rotation to use it as a pivot
Correct answer: after pushing your pencil onto each of the vertices to leave an imprint
after rotating the tracing paper
Q3.
This object will be rotated 90° anti-clockwise with the centre of rotation of (6, 6). Where will the image of vertex A end up after this rotation?
(4, 10)
(8, 6)
(6, 6)
(6, 2)
Q4.
This object will be rotated 180° with the centre of rotation of (6, 6). Where will the image of vertex B end up after this rotation?