Download November 20, 2014 Congruent figures have the same shape and size.

November 20, 2014
A
A
X
C
B
C
B
Z
Triangles ABC and XYZ are congruent.
Vertices match up:
A with X
B with Y
C with Z
Y
X
Z
Y
A
A
X
X
C
B
Y
Z
Triangles ABC and XYZ are congruent.
Corresponding angles:
<A & <X
<B & <Y
<C & <Z
C
B
Z
Triangles ABC and XYZ are congruent.
Corresponding sides:
AB & XY
BC & YZ
AC & XZ
Y
4.1 Congruent Figures
Definition of Congruent Triangles:
Congruent figures
have the same shape and size.
A
B
Two triangles are congruent if and only if
their vertices can be matched up so that
corresponding parts (angles and sides) of
the triangles are congruent.
X
C
Y
Z
November 20, 2014
R
R
A
A
Y
Y
N
U
N
U
Corresponding parts are congruent.
S
Corresponding parts are congruent.
S
R
WHEN NAMING A
POLYGON,
YOU MUST NAME THE
VERTICES IN ORDER!!!!
A
Y
N
U
ΔRAY ≅ ΔSUN
ΔAYR ≅ ΔUNS
ΔYRA ≅ ΔNSU
...
S
Suppose you know that ΔXYZ ≅ ΔABC.
From the definition of congruent triangles
you know, that...
XY ≅ AB
<X ≅ <A
Corresponding parts of congruent
triangles are congruent.
or you can say....
Corr. parts of ≅ Δs are ≅.
or you can say....
CPCTC
November 20, 2014
Two polygons are congruent if and only if
their vertices can be matched up so that
corresponding parts are congruent.
E
B
WHEN NAMING A
POLYGON,
YOU MUST NAME THE
VERTICES IN ORDER!!!!
C
Fill in the blank with always, sometimes, or never.
An acute triangle is _____________ congruent to an obtuse triangle.
R
H
K
A
O
BRAKE ≅ CHOKE
KE is a common side.
Fill in the blank with always, sometimes, or never.
A polygon is _____________ congruent to itself.
Fill in the blank with always, sometimes, or never.
A right triangle is _____________ congruent to another right triangle.
November 20, 2014
Fill in the blank with always, sometimes, or never.
Fill in the blank with always, sometimes, or never.
If ΔABC ≅ ΔXYZ, <A is _____________ congruent to <Y.
If ΔABC ≅ ΔXYZ, <B is _____________ congruent to <Y.
Fill in the blank with always, sometimes, or never.
Suppose ΔTIM ≅ ΔBER. Complete.
If ΔABC ≅ ΔXYZ, AB is _____________ congruent to YZ.
IM ≅ ___________
Suppose ΔTIM ≅ ΔBER. Complete.
Suppose ΔTIM ≅ ΔBER. Complete.
___________ ≅ <R
ΔMTI ≅ ___________
November 20, 2014
Complete.
If ΔABC ≅ ΔXYZ, m<B = 80, and m<C = 50, name four congruent angles.
Complete.
Write six congruences that must be correct when ΔABC ≅ ΔDEF.