Unit 1: Transformations
Day 5: Dilations
 Warm-up
 Homework
Check
 Notes/Activity
 Independent Practice
Individually, rewrite your definitions
WITHOUT using the vocabulary term.
1.
2.
3.
4.
Isometry
Translation
Reflection
Rotation
e.g. Rotation is not “rotating an object”
 One
at a time:
 1 person close your eyes for 15 seconds.
 The other person, watch their eyes as
they open.
 Write down what you notice.
 Repeat with other person.
A
dilation occurs when you resize a
shape
 It
can get
bigger or
smaller.
• but it still looks similar, meaning all angles stay
the same and relative sizes are the same
 Does
a dilation have the property of
isometry?
All Dilations have a scale factor
Scale Factor – describes size change
http://www.mathopenref.com/dilate.html

The dilation is an
enlargement if the scale
factor is greater than 1.

The dilation is a reduction if
the scale factor is between
0 and 1.
Does that work for B to B’ and C to C’?
*c is called the scale factor
A’ or A need to be
either the x’s or
the y’s of one
coordinate,
Unless the
values are zero.
Page 676-678
#7-14, 18-20, 32-35, 38,39, 42
 Come
up with an example or a time you
would see or use a dilation in the real
world.
 Dilation Worksheet