1. Chinese University of Hong Kong
Group Project Two
Communication and Technology
Dr. Fong Lok Lee

2. Form One mathematics
Similar Triangle

3. Target Audience:
Form one student(band three)
Type of software:
pre-lesson self learning package

4. Name List of Group 17 98035520 LAI TUNG LEUNG
SHING YIU MING SUM YEE FEI
TSO KWOK LAI
YEUNG PUI SHAN RITA

5. Cat mother, MiMi, lost her daughters, would you please help her to find her daughters. Her daughters have the similar footprint with their mother.
MiMi’s footprint

6. Contents 1. Introduction of Similar Figures
2. Introduction of Similar Triangles
3. Exercise of Similar Triangles
4. Summary of Similar Triangles
5. Member List

7. Similar Figures
Two figures are similar if they have the same shape but not necessary the same size.
Similar figures
Non-similar figures
Continue

8. The following are similar figures.II

9. III
Back to
Similar Figures IV V

10. The following are non-similar figures.II

11. III
Back to
Similar Figures IV V

12. Now can you find MiMi’s daughters?
MiMi’s footprint

13. Similar Triangles
Two triangles are similar if all their corresponding angles are equal. A X
Next page Z Y B C
A= X, B= Y, A= Z ABC ~ XYZ
(Abbreviation : equiangular s )

14. Two triangles are similar if all their corresponding sides are proportional.X Z A C
Next page Y B
(AB/XY) = (BC/YZ) = (CA/ZX) ABC ~ XYZ
(Abbreviation : 3 sides proportional)

15. Two triangles are similar if two pairs of their sides are proportional and their included angles are equal. A X
Next page Y Z B C
A= X, (AB/XY) = (CA/ZX) ABC ~ XYZ
(Abbreviation : ratio of 2 sides, inc. )

16. The following are non-similar trianglesII
Next page

17. III
Next page IV

18. Which of the following is similar to the above triangle?1.
Which of the following is similar to the above triangle? B A C

19. 2. Give the reason for why the following triangles are similar?
A. A.A.A
B. 3 sides proportional
C. 2 sides proportional and included angle

20. 3. Are the following triangles similar ?B C 7 6 8 4 N M
3.5 3 A
A. Yes
B. No

21. 3. Name the similar triangles and give reasons.B C 7 6 8 M
3.5 3 4 N
A. ABC ~  LNM (3 sides proportional)
B.  ABC ~  MLN (3 sides proportional)
C.  ABC ~  LNM (A.A.A)
D.  ABC ~  MLN (A.A.A)

22. 4. Are the following triangles similar ?
47º A B C
47º
A. Yes
B. No

23. 4. Name the similar triangles and give reasons.
47º A B C
47º
A.  ABC~  LMN (3 sides proportional)
B.  ABC~  MNL (A.A.A)
C.  ABC~  MNL (3 sides proportional)
D.  ABC~  NLM (A.A.A)

24. 5. Are the following triangles similar ?P R Q
46º
3.5 4 A B C
46º 8 7
A. Yes
B. No

25. 6. Name the triangles and give reasons.
51º H B K C
A. Yes
B. No

26. 6. Are the following triangles similar ?
If they are similar, name the triangles and give reasons. A
51º H B K C
A.  AHK~  ABC(A.A.A)
B.  AHK~  ACB(A.A.A)
C.  AHK~  ACB(3 sides proportional)
D.  AHK~  BAC(3 sides proportional)

27. 7. Are the following triangles similar ?
35º
A. yes
B. No

28. 7. Name the similar triangles and give reason.
35º A B C D E
A. ABC ~ CDE (AAA)
B. ABC ~ EDC (AAA)
C. ABC ~ CDE (3 sides proportional)
D. ABC ~ EDC (3 sides proportional)

29. 8. In the figure, the two triangles are similar.
What are x and y ? P B A C 6 7 8 Q R 3 x y
A. x = 3.5 , y = 4
B. x = 3.5 , y = 6
C. x = 4 , y = 3.5
D. x = 4 , y = 5

30. 9. In the figure, the two triangles are similar.
What are c and d ? A B C P Q R 10 6 c 5 4 d
A. c = 8.5 , d = 3
B. c = 8.5 , d = 6
C. c = 8 , d = 6
D. c = 8 , d = 3

31. 10. In the figure, the two triangles are similar.
What are x , y and z ? A B C P Q R 6 8 3 x y z
A. x = 10 , y = 4 , z = 5
B. x = 10 , y = 4 , z = 20
C. x = 10 , y = 16 , z = 5
D. x = 10 , y = 16 , z = 20

32. 3 Conditions of Similar Triangles :
SUMMARY
3 Conditions of Similar Triangles :
1. 3 angles equal
2. 3 sides proportional
3. 2 sides proportional and included equal angles