 # Rotations I

Lesson

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 spun around (like going in a circle). Every point on the original shape has a matching point on the new shape.

Commonly we describe rotations using a degree measure (like an angle), and as being either clockwise or anticlockwise. Particularly at the moment you need to be able to identify rotations of:

$90^\circ$90° (a quarter turn), $180^\circ$180° (a half turn), $270^\circ$270° (a three-quarter turn) and $360^\circ$360° (a full turn) 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.

#### Examples

##### Question 1

Which picture shows a rotation? Think: Which one looks like it has been spun around?

Do:

C has been translated (slid) into a different position.

B looks like a mirror image of the original. So this is a reflection (flip).

A has been spun around $180^\circ$180°. This is the rotation!

##### Question 2

Select all the rotations.

1. A B C D

##### QUESTION 3

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

##### QUESTION 4

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