Page 165 - MAT KS3 Y8 Cambridge CheckPoint

16.2 Enlarging shapes

For question 4 work in a group of three or four.
i On your own, draw the enlargement for part a only of the question.
ii Compare your diagram with the other members of your group. Discuss the different approaches
that you each used to draw the enlargement and decide which ones are correct.
iii Repeat the process for part b, and then part c.

4 Copy each of these shapes onto squared paper.
Enlarge each one, using the given scale factor and centre of enlargement.
a scale factor 2 b scale factor 3 c scale factor 4

For question 5 work in a group of three or four.

i Copy the diagram for each part.
ii For part a only, write down the coordinates of the centre of enlargement and the scale factor.
iii Compare your answer with those of the other members of your group. Discuss the different
approaches that you each used to work out the coordinates and scale factor and decide whose
answers are correct.
iv Repeat the process for part b.
5 Each diagram shows an object and its image after an enlargement.
For each part, write down scale factor and the coordinates of the centre of enlargement.

a y b y
8 8
object
7 7
6
image 6
5 5
4 4 image
object
3
3
2
2
1 1
0 0
01234567 8 9 10 11 12 13 14 x x
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Summary

You should now know that: You should be able to:
★ An enlargement of a shape is a copy of the shape ★ Transform 2D shapes by rotation, reflection and
that changes all the lengths but keeps the same translation, and by simple combinations of these
proportions. All the angles stay the same. transformations.
★ The scale factor tells you how the lengths of the ★ Understand and use the language and notation
shape change and also how far from the centre of associated with enlargement.
enlargement the image is. ★ Enlarge 2D shapes, given a centre of enlargement
and a positive integer scale factor.

16 Position and movement 163