LESSON
Triangle Congruence: SSS and SAS
4-4
Lesson Objectives (p. 242):
______________________________________________________________
______________________________________________________________
Vocabulary
1. Triangle rigidity (p. 242): __________________________________________
______________________________________________________________
2. Included angle (p. 242): __________________________________________
______________________________________________________________
Key Concepts
3. Postulate 4-4-1—Side-Side-Side (SSS) Congruence (p. 242)
POSTULATE
HYPOTHESIS
CONCLUSION
4. Postulate 4-4-2—Side-Angle-Side (SAS) Congruence (p. 243)
POSTULATE
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
HYPOTHESIS
84
CONCLUSION
Geometry
LESSON
Triangle Congruence: SSS and SAS
4-4
Lesson Objectives (p. 242):
apply SSS and SAS to construct triangles and to solve problems; prove
______________________________________________________________
triangles congruent by using SSS and SAS.
______________________________________________________________
Vocabulary
if the side lengths of a triangle are given, the
1. Triangle rigidity (p. 242): __________________________________________
triangle can have only one shape.
______________________________________________________________
angle formed by two adjacent sides of a polygon.
2. Included angle (p. 242): an
__________________________________________
______________________________________________________________
Key Concepts
3. Postulate 4-4-1—Side-Side-Side (SSS) Congruence (p. 242)
POSTULATE
If three sides of one
triangle are
congruent to three
sides of another
triangle, then the
triangles are
congruent.
HYPOTHESIS
CONCLUSION
ABC FDE
A
4 cm
B
D
7 cm
6 cm
4 cm
F
6 cm
C
7 cm
E
4. Postulate 4-4-2—Side-Angle-Side (SAS) Congruence (p. 243)
POSTULATE
If two sides and the
included angle of
one triangle are
congruent to two
sides and the
included angle of
another triangle,
then the triangles
are congruent.
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
HYPOTHESIS
CONCLUSION
ABC EFD
A
D
E
C
F
B
84
Geometry
LESSON 4-4 CONTINUED
5. Get Organized Use the graphic organizer to compare the SSS and SAS
postulates. (p. 245).
SSS
SAS
How are they alike?
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
How are they different?
85
Geometry
LESSON 4-4 CONTINUED
5. Get Organized Use the graphic organizer to compare the SSS and SAS
postulates. (p. 245).
SSS
SAS
How are they alike?
Both postulates use
2 sides and an included
corresponding part.
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
How are they different?
For SSS the included part
is a side; for SAS the
included part is an angle.
85
Geometry