1. Objectives
Prove certain triangles are similar by using AA, SSS, and SAS.
Use triangle similarity to solve problems.

2. There are several ways to prove certain triangles are similar.

5. Example 1
Determine if the triangles are similar. If so, tell why and write the similarity statement and similarity ratio.
Similar : Y or N
Why:_________
Similarity Statement:____~____
Similarity Ratio:__________
SAS ~
ΔMJN
ΔKJL

6. Example 2
Determine if the triangles are similar. If so, tell why and write the similarity statement and similarity ratio.
Similar : Y or N
Why:_________
Similarity Statement:____~____
Similarity Ratio:__________
SSS ~
ΔPQR
ΔPRS

7. Example 3
Determine if the triangles are similar. If so, tell why and write the similarity statement and similarity ratio.
Similar : Y or N
Why:_________
Similarity Statement:____~____
Similarity Ratio:__________
AA ~
ΔCBA
ΔHGF
none

8. Example 4
Determine if the triangles are similar. If so, tell why and write the similarity statement and similarity ratio.
Similar : Y or N
Why:_________
Similarity Statement:____~____
Similarity Ratio:__________
AA ~
ΔQST
ΔRSP
none

9. Do Part 1 assignment
You have _____ minutes.

11. Example 1
Complete the proportions V I D E O EO DO

12. Example 2
Complete the proportions P A Y E S L R ER LR YR YE

13. Example 3
Solve
Top part
Bottom part x
X = 30

14. Example 4
Solve
Top part
Bottom part x
X = 6.25

15. Example 5
Solve
Small Triangle V I D E O x 5 8 20
Big Triangle
X = 7.5

17. Example 6
Find RV
X = 3

18. Example 7
Find x
y = 3

19. Example 8
Given that ΔAOB ~ ΔCOD, find the coordinates of D and the scale factor. 4 2
X = 6 3
D(6, 0) ?
Scale factor 2

20. Example 9
Given that ΔAOB ~ ΔCOD, find the coordinates of C and the scale factor.
X = 25
C(25, 0)
Scale factor 2.5

21. Do Part 2. (2 pages)
What you do not finish is homework!