Download 7.3 Notes - Garnet Valley School District

Geometry B
Date: ____________
7.3 Triangle Similarity
Objective: Prove certain triangles are similar by using AA, SSS, and SAS.
Use triangle similarity to solve problems.
Recall from Chapter 4: There were 5 ways to prove two triangles were congruent.
1. ____________ 2. ____________ 3. ____________ 4. ____________ 5. ____________
In Chapter 7, we will learn 3 ways to prove triangles are similar.
AA: ________ - __________ Similarity
If two angles in one triangle are _____________ to two
angles in another triangle, then the two triangles are
similar.
Ex. 1: Using AA Similarity
Explain why the triangles are similar and write a similarity statement.
a.
b.
SSS: ________ - __________ - __________ Similarity
If the three sides of one triangle are ________________ to
the three corresponding sides of another triangle, then the
triangles are similar.
SAS: ________ - _________ - _________ Similarity
If two sides of triangle are _________________ to two sides
of another triangle, and their included angles are
_____________, then the triangles are similar.
Ex. 2: Verifying Triangle Similarity
Verify that the two triangles are similar. State the reason why and write the similarity statement.
a.
b.
c.
Ex. 3: Finding Lengths in Similar Triangles
Explain why ∆ABE ~ ∆ACD, and then find CD.
Practice: Explain why ∆RSV ~ ∆RTU and then find RT.
HW: 7.3 Worksheet