1. 4-2 Triangle congruence by sss & sas
GEOMETRY

2. Side-Side-Side (SSS) Postulate
If 3 sides of one triangle are congruent to the 3 sides of another triangle, then the 2 triangles are congruent
∆𝐺𝐻𝐹≅∆𝑃𝑄𝑅

3. Ex. 1) Is there enough information to prove the 2 triangles are congruent?
Given: 𝑨𝑩 ≅ 𝑩𝑪 , 𝑨𝑫 ≅ 𝑪𝑫 Plan: 3 sides need to be congruent

5. Side-Angle-Side (SAS) Postulate
If 2 sides and the included angle of one triangle are congruent to 2 sides and the included angle of another triangle, then the 2 triangles are congruent
∆𝐴𝐵𝐶≅∆𝐸𝐹𝐷

6. Ex. 2) What other information do you need to prove ∆𝑹𝑺𝑲≅∆𝑻𝑲𝑺?

7. Ex. 3) What other information do you need to prove ∆𝑨𝑩𝑪≅∆𝑪𝑫𝑨 by SAS?

8. Ex. 4) From the information given, can you prove the triangle congruent?

9. Ex. 5) From the information given, can you prove the triangle congruent?