Page 161 - MAT KS3 Y8 Cambridge CheckPoint

16.1 Transforming shapes

16.1 Transforming shapes

You can already transform 2D shapes by reflecting, translating or rotating them. You can also use a
combination of transformations to transform a shape.

Worked example 16.1
y
The diagram shows a triangle A. 6
Draw the image of triangle A after: 5 A
a reflection in the line y = 4; label the image B 4
b translation 3 squares right and 2 squares down; label the image C 3
c rotation of 180 ° about the point (4, 5); label the image D
d rotation of 90 ° clockwise about the centre of rotation at (1, 5), followed 2
by reflection in the line x = 2; label the image E. 1
0
01234567 x

y a Draw the line y = 4 (shown in red). Draw the reflection of triangle A in the
6 red mirror line. Label the image B.
A
5 b Move triangle A three squares right and two squares down (shown by the
E D
4 green arrows). Label the image C.
C
3 c Use tracing paper to trace triangle A. Put the point of your pencil on the
B
2 tracing paper over the point (4, 5) and turn your tracing paper 180 °. Draw
1 the image of A and label it D.
0 d Use tracing paper to trace triangle A. Put the point of your pencil on
01234567 x the tracing paper over the point (1, 5) and turn your tracing paper 90 °
clockwise. Draw the image (shown in blue). Draw the line x = 2 (shown in
orange). Draw the reflection of the blue triangle in the orange mirror line.
Label the image E.

✦ Exercise 16.1

1 Copy each diagram. Add the mirror line with the given equation. Reflect the shape in the
mirror line.

a y b y c y
6 6 6
5 5 5
4 4 4
3 3 3
2 2 2
1 1 1
0 0 x 0
0 1 2 3 4 5 6 7 x 01234567 01234567 x

mirror line x = 4 mirror line y = 3 mirror line x = 3.5

16 Position and movement 159