Determine if the polygons are similar. If so, write the similarity statement and scale factor.

Identify the congruent angles.

Compare the ratios

To Start: 18 Points

J

M

L

K

W

T U

V

8

2

8

46

2424

12

WMVLUKTJ ,,,

1

3

2

6

TW

JM

1

3

8

241

3

8

24

UV

KL

1

3

4

12

VW

LMTU

JK

1!:3 isfactor scale theandTUVW ~JKLM

thereforeequal, are ratios theAll

CHAPTER 7: SIMILARITY

Section 7.3: Proving Triangles Congruent

Postulate 7.1 AA∼

Using AA∼ Postulate Are the two triangles similar?

Why?

∠R≅∠V Both are 45o

∠RSW≅∠VSB Vertical ∠’s

So, ∆RSW∼ ∆VSB AA∼ Postulate

Using AA∼ Postulate Are the two triangles similar?

Why?

∠L≅∠R Both are 70o

∠K=180-70-30=80 ∠P=180-85-70=25

So, ∆RSW and ∆VSB are not Similar

Using AA∼ Postulate

YES NO

Theorem 7-1 SAS∼

Verifying Triangle Similarity

Are the triangles similar? If so, write the similarity statement.

∠K≅∠K Reflexive

So, ∆KLP∼∆KMN by SAS∼

5

4

10

8

KM

KL

5

4

15

12

KN

KP

Theorem 7-2 SSS∼

Verifying Triangle Similarity

Are the triangles similar? If so, write the similarity statement.

All three ratios are equal, so, ∆STU ∼∆VSB by the SSS∼ Theorem.

Using SAS∼ and SSS∼

YES! ∆ABC ∼∆EFG by SSS∼ YES! ∆ALW ∼∆ACE by SAS∼

Homework!!

Page 455:

1-3, 7-12, 24-26

7.3 Worksheet