Materials
DE Marker
10 Small White Boards
Reminders
The two triangle below are Similar. What is
the scale factor from Triangle A to Triangle B,
and from Triangle B to Triangle A:
25
15
A
B
Get out your agenda if you see
your name below. You need to
come to my room tomorrow.
Period 4
Period 5
Period 6
Stretching and Shrinking:
Using Similar Triangles
How do I use similar
triangles to find
distances?
Questions:
How do name a
triangle?
Notes:
List all three letters that correspond to each angle in
alphabetical order (if possible).
B
A
C
Example: The above triangle could be named, Triangle
ABC
Questions:
How do I find
the scale factor
FROM one
figure To
another figure?
Notes:
Use the formula
𝑁𝑒𝑤
𝑂𝑙𝑑
where Old is the length of a side on the “FROM” figure
and New is the length of a corresponding side on the TO
figure
Example:
30
20
A
B
Activity
1. Read the problem on page 63 in you textbook
2. Using a White Board, work in groups of 2 and answer problems
A-C
3. Be prepare to share with the class
Homework
WS Scale Factor and
Finding Distances
AND Cornell Notes
Summary