Page 388 - Math Smart - 7

Help ^ Transformations

Sheet A transformation is a change in the position of an object.

Translation Reflection

A translation moves every point on a shape the A reflection produces a mirror image of a shape
same distance in the same direction. along a line of reflection.

/
\ H :
\ /
r
> \ llr e 0
\ A
\
s ^re lec ion
N /
->-JC
s -4 -3 - N
-
N \ \
/ \
|^H>
/
ig^W
/
/ s
Shape D is the reflection of shape C along the
Shape A has been translated -6 units along the
line y^x. Both shapes are the same perpendicular
jc-axis and 3 units up along they-axis to shape B.
distance away from the line of reflection.

A rotation turns a shape about a fixed point. To perform or describe a rotation, three details
are needed:
• centre of rotation
• angle of rotation

• direction of rotation (clockwise or anti-clockwise)
When a shape is rotated, ail points in the shape rotate through the same angle.
The distance from the centre of rotation to a point on the object is that same as the distance
from the centre of rotation to the corresponding point on the image.

r~^
c'i I.

y X

A < C
^x
5 4 - 3 -2 -1 * ;
n

In this example, the object triangle ABC is rotated 90° anti-clockwise about the origin (0, 0).
The image and the object remains the same (congruent) after translation, reflection or rotation.

UNIT 16 I Transformation