Page 129 - Math Course 2 (Book 2)

Congruent Triangles
Mo. 10

Lesson 3 Key Concept

Corresponding Parts of
KEY CONCEPTS: Congruent Triangles

1. Identify congruent triangles and Words If two triangle are congruent, their
corresponding parts of congruent corresponding sides are congruent
triangles. and their corresponding angles are
congruent.
Y
Model Slash marks are
used to indicate
MO. 10 - L3a which sides are
congruent.
Identify Congruent Triangles Q
and Their Parts X Z

Arcs are used to
indicate which
Vocabulary A-Z angles are
congruent.
Let us learn some vocabulary P R
Symbols Congruent Angles :

congruent ∠X ≅ ∠P, ∠Y ≅ ∠Q, ∠Z ≅ ∠R

Figures that have the same size and shape are
congruent. Congruent Sides :
C E
XY ≅ PQ, YZ ≅ QR, XZ ≅ PR

A D Let’s Begin
B F

corresponding parts
The parts of congruent triangles that “match” are Name Corresponding Parts
corresponding parts.
Example
Y

Name the corresponding parts in the congruent
Tick marks are used triangles shown. Then complete the congruence
to indicate which statement.
sides are congruent.
D H
X Z
Q
Arcs are used to
indicate which angles
are congruent.
E F I G
△HGI ≅ ?

P R
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