1. Prove Triangles Similar by SSS and SAS
Geometry Sections 6.5
Prove Triangles Similar by SSS and SAS

2. Side-Side-Side (SSS) Similarity Theorem (Theorem 6.2)
If the corresponding side lengths of two triangles are proportional, then the triangles are similar

3. Example 1: Is either ∆ DEF or ∆ GHJ similar to ∆ ABC?
Step 1: Compare ∆ ABC and ∆ DEF by finding ratios of corresponding side lengths.
Shortest sides Longest sides Remaining sides
Step 2: Compare ∆ ABC and ∆ GHJ by finding ratios of corresponding side lengths.

4. Example 2:
Find the value of x that makes triangle ABC ~ triangle DEF.

5. Example 2 (Con’t):
Find the value of x that makes triangle ABC ~ triangle DEF.

6. Side-Angle-Side (SAS) similarity Theorem (Theorem 6.3)
If an angle of one triangle is congruent to an angle of a second triangle and the lengths of the sides including these angles are proportional, then the triangles are similar

7. Use the SAS Similarity Theorem
Example 4: Example 5:
Is ∆ FDM ~ ∆AVQ? Is ∆ GHK ~ ∆ NMK?
YES
YES

8. Examples
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