Page 111 - Cambridge+Checkpoint+Mathematics+Coursebook+9

12 Tessellations, transformations and loci

Here are nine wallpaper patterns.
Key words
Make sure you learn and
understand these key words:
tessellation
column vector
locus
loci

In the !rst pattern a shape has been translated to di"erent positions.

In the second pattern a shape has been rotated through 180° degrees to a di"erent position.

In the fourth pattern you can extend it by re! ection in the thick vertical lines.
Can you see examples of translation, rotation and re#ection in the other patterns?

H ere is another repeating wallpaper pattern.

Look carefully. $ere is a pattern with three #owers on the le%. What symmetry does this have?

$e three-#ower pattern on the le% is rotated to form the middle three-#ower unit. Where is the centre

of rotation? What is the angle of rotation?

$e three-#ower pattern on the le% can be re#ected or translated to give the three-#ower pattern on the

right. Where is the mirror line for the re#ection? How will the pattern continue?

In this unit you will carry out more transformations of 2D shapes, and learn how to describe combined
transformations of 2D shapes. You will also learn about tessellating shapes and about loci.
110 12 Tessellations, transformations and loci