Skip to main content
By Michael Sithole
201114682
Rotation
Turn!
Reflection
Flip!
Translation Slide!
After any of those transformations (turn, flip or slide), the shape still has the same
size, area, angles and line lengths.
 Let us first revise the
plotting of points on the
cartesian plane.
 Plot the following points
on the grid provided.
 A(2;4), B(-3;6),C(-5;-6),
 D(6;-4)
 Now translate each point 2
units to the right and 1 unit
downward.
 Consider ∆ABC in the figure
alongside.
 ∆ABC has been translated 10
units to the left to form the
image ∆A’B’C’.
 You will notice that the three
vertices of the ∆ABC has moved
10 units to the left.
 A has moved 10 units left to
form A’.
 B has moved 10 units left to
form B’.
 C has moved 10 units left to
form C’.
 ∆ABC is congruent to ∆A’B’C’.
They are identical in size and
shape.
 Consider ∆ABC in the figure below.
 ∆ABC has been translated 9units
downwards to form the image
∆A’B’C’.
 You will notice that the three
vertices of the ∆ABC has moved
9units downward.
 A has moved 9 units downward to
form A’.
 B has moved 9 units downward to
form B’.
 C has moved 9 units downward to
form C’.
 ∆ABC is congruent to ∆A’B’C’. They
are identical in size and shape.
 In this example, ABC has first
translated 11 units to the left and
then 9 units downwards.
 Notice that the three vertices
have moved 11 units to the left
and then 9 units downwards.
 A has moved 11 units to the left
and then 9 units downward to
form A‘
 B has moved 11 units to the left
and then 9 units downward to
form B‘
 C has moved 11 units to the left
and then 9 units downward to
form C‘
 Clearly, figure ABC is congruent
to A'B'C’ since they are identical
in size and shape.
 Translate figure ABCD
as follows 9 units to
the left and 1 unit
upwards.
 Translate A’B’C’D’ as
follows 1 unit to the
right and 9 units
downward.
"Rotation" means turning around a center:
The distance from the center to any point on the shape stays the same.
Every point makes a circle around the center.
Every point is the same distance from the central line !
... and ...
The reflection has the same size as the original image
The central line is called the Mirror Line ...
1. Measure from the point to the mirror line (must hit the mirror line at a right angle)
2. Measure the same distance again on the other side and place a dot.
3.Then connect the new dots up!
Resizing
The other importantTransformation is Resizing (also called dilation,
contraction, compression, enlargement or even expansion).The shape
becomes bigger or smaller:
Resizing Resize! If you have to use Resizing to make one shape
become another then the shapes are not Congruent, they are Similar.