1. 6.5 – Prove Triangles Similar by SSS and SAS

2. Side-Side-Side Similarity (SSS~):
Two triangles are similar if the 3 corresponding side lengths are proportional A D C E F B

3. Side-Angle-Side Similarity (SAS~):
Two triangles are similar if 2 corresponding sides are proportional and the included angle is congruent A D C E F B

4. 1. Verify that ABC ~ DEF. Find the scale factor of ABC to DEF.
ABC: AB = 12, BC = 15, AC = 9
DEF: DE = 8, EF = 10, DF = 6 A 9 12 D
Scale Factor: 8 6 C E 10 F B 15

5. 2. Is either LMN or RST similar to ABC? Explain.
ABC ~ RST by SSS~

6. 3. Determine whether the two triangles are similar
3. Determine whether the two triangles are similar. If they are similar, write a similarity statement and find the scale factor of Triangle B to Triangle A.
L  X
YES or NO
______ ~ ______
Scale Factor:
YXZ
JLK

7. 3. Determine whether the two triangles are similar
3. Determine whether the two triangles are similar. If they are similar, write a similarity statement and find the scale factor of Triangle B to Triangle A.
YES or NO
______ ~ ______
Scale Factor:

8. GKH  NKM YES or NO Reason: ___________ SAS ~ 15 4 6 10
4. Determine whether the triangles are similar. If they are similar, state which postulate or theorem that justifies your answer. Show all work! 15 4 6 10
GKH  NKM
YES or NO
Reason: ___________
SAS ~

9. ABC  DEC B  E YES or NO Reason: ___________ AA ~
4. Determine whether the triangles are similar. If they are similar, state which postulate or theorem that justifies your answer. Show all work!
ABC  DEC
B  E
YES or NO
Reason: ___________
AA ~

10. YES or NO Reason: ___________
4. Determine whether the triangles are similar. If they are similar, state which postulate or theorem that justifies your answer. Show all work!
YES or NO
Reason: ___________

11. HW Problem #10 18 15 16.5 24 20 ∆HGJ ~ ∆HFK By SSS~ 22 6.5 391-394
Section
Page #
Assignment
Spiral
6.5
3-11, 15, 16, 33 (a & b only)
#10 15 18
16.5 20 24
∆HGJ ~ ∆HFK
By SSS~ 22