Transcript Document

3.5 warm-up 2
Which of the following equations is
equivalent to y=4x-8 ?
a.y=x-2
b. y=2x-4
c. 3y=12x-24
d. y/2=2x-16
4.1 Congruent Figures
You will justify
and apply
polygon
congruence
relationships
You will name and
label
corresponding
parts of congruent
polygons
Happy Thanksgiving
First, we need to look
at some things.
 What makes two items
congruent?
 All the corresponding
sides are congruent.
 All the corresponding
angles are congruent.
Pardekooper
Labeling an angle
or a side in correct
order is very
important.
Lets see if you can
do it.
Pardekooper
LMCBJK. Complete the
following statements.
BK
1. LC_____
CM
2. KJ_____
ML
3. JB_____
B
4. L_____
C
5. K_____
J
6. M_____
KJB
7. CML_____
CLM
8. KBJ_____
9. MLC_____
JBK
MCL
10. JKB_____
Pardekooper
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
Pardekooper
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
Pardekooper
There is a theorem.
If two angles of one triangle
are congruent to two
angles of another triangle,
then the third angle is
congruent
Pardekooper
Next comes a proof. {Remember
Remember
to label all of the given.}
all parts must
be congruent.
Given: PQPS, QRSR, QS,
S
QPRSPR
Prove: PQR PSR
R
X
P
Q
Statement
Reason
1. PQPS, QRSR
1. Given
2. PRPR
2. Reflexive
3. QS,
3. Given
QPRSPR
4. QRPSRP
5. QRPSRP
Pardekooper
4. If 2 ’s are , then 3rd  is 
5. All parts  , figures are 
What do you need to prove the
following triangles congruent?
3rd pair of ‘s 
3rd pair of sides 
Pardekooper