Download Unit 4.2

UNIT 4: CONGRUENT TRIANGLES
4.2 – Congruence and Triangles
Identifying
Congruent Figures
Definition of
Congruent Figures
MA30: GEOMETRY
(Text Ref: Ch 4.2 Pg 202-210)
I. Identifying Congruent Figures
A. Definition of Congruent Figure
Two figures are congruent if their ___________________ are
congruent and ___________________ are congruent.
B. Determining Congruent Shapes
1) Determine which shape(s) are congruent to the first figure.
Determining
Congruent Shapes
figure 1
figure 2
figure 3
figure 4
C. Naming Congruent Parts
Corresponding
Angles
Sides
Naming Congruent
Parts
D. Write the Congruence Statement for the Triangles
Writing Congruence
Statements
E. Theorem 4.3 – Third Angles Theorem
Theorem 4.3
Third Angles
Theorem
If two angles of one triangle are congruent to two angles of another
triangle, then the third angles are also congruent.
B
E
A
C
D
F
Using Properties of Congruent Figures – Find the value of the variables.
1) ABC  DEF
2) ABCDE  FGHIJ
Using the Third Angles Theorem – Find the value of x.
3)
4)
II. Theorem 4.4 – Properties of Congruent Triangles
B
Reflexive Property of Congruent Triangles
A
C
E
Symmetric Property of Congruent Triangles
D
F
K
Transitive Property of Congruent Triangles
J
L