This document discusses two theorems for proving triangle similarity: the SSS Similarity Theorem and the SAS Similarity Theorem. The SSS Similarity Theorem states that if three corresponding sides of two triangles are proportional, then the triangles are similar. The SAS Similarity Theorem states that if one angle of one triangle is congruent to one angle of another triangle and their included sides are proportional, then the triangles are similar. Examples are provided to illustrate each theorem.

1. 6.5 SSS & SAS Similarity Theorems November 26, 2012
Bellwork
Determine if 2 triangles are similar. If they are, write a similarity
statement.
2.
Yes; ABE ~ ACD no
Find the length of BC
4. A tree casts a shadow that is 30 feet
long. At the same time a person standing
nearby,who is five feet two inches tall,
casts a shadow that is 50 inches long. How
tall is the tree to the nearest foot?
37 ft
7.5
Nov 29­3:09 PM
HW pg. 391 #4­22 evens & 37 1

2. 6.5 SSS & SAS Similarity Theorems November 26, 2012
6.5 Prove Triangles Similar by SSS & SAS
SSS Similarity Theorem:the corr. sides of 2
If s are proportional, then the s are ~.
A R
If AB = BC = CA, then ABC ~ RST
RS ST TR
S T
C
B
Nov 29­3:25 PM
HW pg. 391 #4­22 evens & 37 2

3. 6.5 SSS & SAS Similarity Theorems November 26, 2012
Nov 29­3:33 PM
HW pg. 391 #4­22 evens & 37 3

4. 6.5 SSS & SAS Similarity Theorems November 26, 2012
SAS Similarity Theorem:an < ≅ to another < in 2nd
If is and the included sides
M
are proportional, then the are ~.
X
If <X≅<M & ZX= XY then XYZ ~ MNP
,
PM MN
P N
Z Y
Nov 29­3:37 PM
HW pg. 391 #4­22 evens & 37 4

5. 6.5 SSS & SAS Similarity Theorems November 26, 2012
Nov 29­3:46 PM
HW pg. 391 #4­22 evens & 37 5

6. 6.5 SSS & SAS Similarity Theorems November 26, 2012
p g. #4­22 evens & 37
W
H 391
Nov 29­3:47 PM
HW pg. 391 #4­22 evens & 37 6