Transcript Learning Math Dilations

Transformation Geometry
Dilations
What is a Dilation?

Dilation is a transformation that produces a
figure similar to the original by proportionally
shrinking or stretching the figure.
Dilated PowerPoint Slide
Proportionally
Let’s take a look…
And, of course,
increasing the
circle
When a figure is dilated, it must be
proportionally
largera or
smaller
increases
the
So,
we always
have
circle
with a
diameter.
than thediameter.
original. We are just
certain
changing
the size or scale.
Decreasing
the
We have a circle
size of the
with a certain
circle
diameter.
decreases the
diameter.
 Same
shape, Different scale.
Which of these are dilations??
A
C
HINT: SAME SHAPE, DIFFERENT SIZE
D
B
Scale Factor and Center of
Dilation
When we describe dilations we use the terms scale factor and
center of dilation.


Scale factor
Center of Dilation
Here we have Igor. He is 3 feet
tall and the greatest width
across his body is 2 feet.
He wishes he were 6 feet tall
with a width of 4 feet.
His center of dilation would be where the
He wishes he were larger by a
length and greatest width of his body
scale factor of 2.
intersect.
Scale Factor


If the scale factor is larger than 1, the figure
is enlarged.
If the scale factor is between 1 and 0, the
figure is reduced in size.
Scale factor > 1
0 < Scale Factor < 1
Are the following enlarged or reduced??
C
A
Scale factor of 1.5
D
B
Scale factor of 0.75
Scale factor of 1/5
Scale factor of 3
The Object and the Image
B’



The original figure is
called the object and
the new figure is called
the image.
The object is labeled
with letters.
The image may be
labeled with the same
letters followed by the
prime symbol.
Image
C’
A’
B
Object
A
C
Dilations Used Everyday
Remember


Dilations are enlargements or reductions.
What are some things that you would not
mind dilating to make larger or smaller?
Practice Dilation Quiz