Download Holt Geometry 7-3

7-3 Triangle Similarity: AA, SSS, and SAS
Objectives
Prove certain triangles are similar by
using AA, SSS, and SAS.
Use triangle similarity to solve problems.
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
There are several ways to prove certain triangles are
similar.
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Example 1
• Determine if the
triangles are similar. If
so, tell why and write
the similarity
statement and
Similar : Y or N
similarity ratio.
Why:_________
SAS ~
ΔKJL ΔMJN
Similarity Statement:____~____
1
Similarity Ratio:__________
3
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Example 2
• Determine if the triangles are similar. If so,
tell why and write the similarity statement
and similarity ratio.
Similar : Y
or
N
SSS ~
Why:_________
ΔPQR ΔPRS
Similarity Statement:____~____
2
Similarity Ratio:__________
3
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Example 3
• Determine if the triangles are similar. If so,
tell why and write the similarity statement
and similarity ratio.
Similar : Y
or
N
AA ~
Why:_________
ΔCBA ΔHGF
Similarity Statement:____~____
Similarity Ratio:__________
none
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
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:_________
AA ~
ΔQST ΔRSP
Similarity Statement:____~____
Similarity Ratio:__________
none
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Do Part 1 assignment
• You have _____ minutes.
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Example 1
• Complete the proportions
ID DE

IV EO
D
I
V
Holt Geometry
E
O
ID DE

DV DO
7-3 Triangle Similarity: AA, SSS, and SAS
Example 2
• Complete the proportions
Y
L
A
P
Holt Geometry
E
R
S
AY YE

LA ER
AY AE

YR LR
LY YR

PL RS
PA AY

ES YE
AY YE

LA
7-3 Triangle Similarity: AA, SSS, and SAS
Example 3
• Solve
Top part
Bottom part
x
Holt Geometry
32 40

24 x
X = 30
AY YE

LA
7-3 Triangle Similarity: AA, SSS, and SAS
Example 4
• Solve
8 5

Bottom part 10
x
Top part
x
Holt Geometry
X = 6.25
AY YE

LA
7-3 Triangle Similarity: AA, SSS, and SAS
Example 5
• Solve
x
V
Holt Geometry
I
5
Small Triangle
D
8
20
Big Triangle
E
O
5
8

5  x 20
X = 7.5
7-3 Triangle Similarity: AA, SSS, and SAS
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Example 6
• Find RV
x  2 10

2 x  1 14
X=3
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Example 7
• Find x
2y
4y  2

14.4
24
y=3
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Example 8
• Given that ΔAOB ~ ΔCOD, find the coordinates of D and
the scale factor.
2 3

4 x
4
2
X=6
3
?
D(6, 0)
Scale factor 2
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
Example 9
• Given that ΔAOB ~ ΔCOD, find the coordinates of
C and the scale factor.
15 x

6 10
X = 25
C(25, 0)
Scale factor 2.5
Holt Geometry
7-3 Triangle Similarity: AA, SSS, and SAS
• Do Part 2. (2 pages)
• What you do not finish is homework!
Holt Geometry