1. 4.2: Triangle Congruency by SSS and SAS
Objectives: Students will be able to…
Prove two triangles congruent using the SSS and SAS Postulates.

2. Side-Side-Side (SSS)Postulate
If 3 sides of one triangle are to 3 sides of another triangle, then the triangles are . (Notice the order in which the congruency statement is given)

3. What else do we know is congruent? Which two triangles are congruent? B C A D
What else do we know is congruent?
Which two triangles are congruent?
3. How do you know?

4. Included Angles and Sides
is included between Angle B and Angle X
is included between NB and NX. B X
Which side is included between angle N and angle B?
Which angle is included between BX and NX?

5. Side-Angle-Side (SAS) Postulate
If 2 sides and the included angle of one triangle are to 2 sides and the included angle of another triangle, then the 2 triangles are
Side-Angle-Side (SAS) Postulate
Again, notice the order of the congruency statement.

6. Name the triangle congruence postulate, if any, that you can use to prove each pair of triangles congruent. Then write a congruency statement. K L Q P O M N 3. J M N A S R P C

7. 1. What other information do you need to prove by SSS?7 A B 6 8 C D 7
2. From the information given, can you prove ? Explain. D E B A C