Download SB En Geom 7-3 Completed.notebook

SB En Geom 7­3 Completed.notebook
Lesson 7­3
October 30, 2012
Proving Triangles Similar
Postulate 7­1
Angle­Angle Similarity (AA~) Postulate
If two angles of one triangle are congruent two to angles of another triangle, then the triangles are similar. P
T
ΔTRS ~ ΔPLM
SL
R
M
Dec 3­7:38 AM
Expl 1. Explain why the triangles are similar. W
45o
45o
R
S
V
B
Ckpt 1. Do you have enough information to find a similarity ratio? Explain.
Dec 3­7:42 AM
1
SB En Geom 7­3 Completed.notebook
Thm 7­1
October 30, 2012
Side­Angle­Side Similarity (SAS~) Thm.
If an angle of one triangle is congruent to an angle of a second triangle, and the sides including the two angles are proportional, then the triangles are similar.
Thm 7­2
Side­Side­Side Similarity (SSS~) Thm.
If the corresponding sides of two triangles are proportional, then the triangles are similar. Dec 3­7:45 AM
Expl 2. Are the triangles similar? If so, write a similarity statement.
Z
P
8
6
Q
3 R
X
4
Y
Ckpt 2. Explain why the triangles must be similar. Write a similarity statement. G
9
B
A
8
8
6
6
C
E
12
F
Dec 3­7:48 AM
2
SB En Geom 7­3 Completed.notebook
October 30, 2012
Extra 1. Are the triangles similar? If so, write the similarity statement.
M
T
AB MX
K
A
58
58o
B
o
X
Extra 2. Are the triangles similar? If so, write the similarity statement.
W
24
Z 18
V
12
36
X
Y
Dec 3­7:52 AM
Expl 3. Find the missing side.
A
12
10
B
C
16
A) 10
24
D B) 15
C) 32
18
E
Ckpt 3. Find x.
D) Not similar.
12
6
x
8
Dec 3­8:17 AM
3
SB En Geom 7­3 Completed.notebook
October 30, 2012
indirect measurement ­ using similar figures to find a difficult measurement
Expl. 4 Find x, the height of the geyser.
x
6
7
40.5
Ckpt 4. Find the height of the cactus. 6
x
4 ft
9 ft
Dec 3­8:21 AM
Homework
Lesson 7-3
2-38E, 45, 46
Dec 3­8:24 AM
4