Transcript Notes 1-5-15

1-5-15
Unit 7 Congruency and
Similarity
Congruent
Figures and
Triangles
1
First, we need to look
at some things.
 What makes two figures congruent?
 All the corresponding sides are congruent.
 All the corresponding angles are congruent.
D
E
C
A
 How many ways can you name
pentagon DCBAE?
10
B
Do it.
Pick a vertex and go clockwise
Pick a vertex and go counterclockwise
DCBAE
DEABC
CBAED
CDEAB
BAEDC
BCDEA
AEDCB
ABCDE
EDCBA
EABCD
Name corresponding parts
 Name all the angles that correspond:
D corresponds to
C corresponds to
B corresponds to
A corresponds to
E corresponds to
I
J
K
P
H
I
D
H
E
C
A
B
DCBAE
J
P
K
IJKPH
• Name all the segments that correspond:
DC corresponds to IJ
CB corresponds to JK
BA corresponds to KP
AE corresponds to PH
ED corresponds to HI
How many
corresponding
angles are
there?
5
How many
corresponding
sides are there?
5
Naming & Comparing Polygons
D
♥ List vertices in order, either
clockwise or counterclockwise.
♥ When comparing 2 polygons,
begin at corresponding
vertices; name the vertices in
order and; go in the same
direction.
♥ By doing this you can identify
corresponding parts.
D corresponds to  I
AE corresponds to PH
E
C
A
B
DCBAE
I
H
J
P
K
IJKPH
Polygon Congruence Rule
If each pair of corresponding angles is
congruent, and each pair of corresponding
sides is congruent, then the two polygons
are congruent.
 What makes two figures
congruent?
 All the corresponding
sides are congruent.
 All the corresponding
angles are congruent.
Congruence Statements
A
B
 Given: These polygons are
congruent.
 Remember, if they are congruent,
they are EXACTLY the same.
D
E
C
H
G
ABCD ~
= EFGH
 That means that all of the
corresponding angles are
F
congruent and all of the
corresponding sides are
congruent.
 DO NOT say that ‘all
the sides are
congruent” and “all
the angles are
congruent”, unless it
is given or
marked.NOT because
it “LOOKS like it.
LMCBJK. Complete the following
statements.
BK
1. LC_____
Labeling an angle or a side in
correct order is very important.
CM
2. KJ_____
ML
3. JB_____
B
4. L_____
C
5. K_____
J
6. M_____
KJB
7. CML_____
CLM
8. KBJ_____
JBK
9. MLC_____
MCL
10. JKB_____
Lets see if you can
do it.
Lets label the
congruent parts
L
P
N
M Q
R
N R
NL  RP
L P
LM PQ
M Q
NM RQ
NLM  RPQ
Now it’s you turn to label
all the congruent parts
for the triangles.
S
F
A
T
B
C
A C
AS  CF
S F
ST FB
T B
TA BC
AST  CFB