 # Rotations

Lesson

## Rotation

A rotation is what occurs when we turn an object or shape around a central point.  The object is exactly the same shape and size, just rotated around (like going in a circle). Every point on the object or shape has a corresponding point on the image.

Commonly we describe rotations using a degree measure, and as being either clockwise or anticlockwise.

Particularly at the moment you need to be able to identify rotations of:

$90^\circ$90°, $180^\circ$180°, $270^\circ$270° and $360^\circ$360° in both clockwise and anticlockwise directions.

Have a play with this interactive. Here you can change the shape that of the object and the position of the central rotation point. Notice how a rotation of $360^\circ$360° takes you right back to where you started.

Here are some worked examples.

##### Question 1

Which of the following figures represents the given flag after rotating it anticlockwise around the red point by 90° ? 1. A B C D A B C D

##### Question 2

Which is the correct image after the original is rotated by $45^\circ$45° clockwise? 1. $B$B

A

$M$M

B

$H$H

C

$A$A

D

$B$B

A

$M$M

B

$H$H

C

$A$A

D

##### Question 3

What is the clockwise angle of rotation of the original image about point $O$O? 1. $\editable{}$°

### Outcomes

#### GM4-8

Use the invariant properties of figures and objects under transformations (refl ection, rotation, translation, or enlargement)