Geometry Section 8.3 Similar Triangles

Geometry

Section 8.3

Similar Triangles

Shortcuts for proving triangles similar

Including AA, SAS and SSS

​What does similar mean?

• ​Similar shapes are shapes that each side is scaled up by the same amount (proportional) and all angles are congruent/the same

Fill in the Blanks

Fill in the Blanks

Fill in the Blanks

Multiple Choice

Are the triangles similar?

• Yes
• No

Multiple Choice

Are the triangles similar?

• Yes
• No

Multiple Choice

Which triangles are similar to triangle A?

• B

• C

• Both

• None

Multiple Choice

Which triangles are similar to triangle A?

• B

• C

• Both

• None

Multiple Choice

State if the triangles in each pair are similar. If so, state how you know they are similar.

• Yes, AA Similarity

• Yes, SSS Similarity

• Yes, SAS Similarity

• Not Similar

Multiple Choice

If the triangles are similar, state how.

• SSS

• SAS

• AA

• Not similar.

Multiple Choice

State the postulate that proves these triangles are similar.

• SSS
• AA
• SAS
• Not similar

Multiple Choice

State the similarity.

• MLV

• VLM

• VML

• Not similar

​Conditions for similar triangles

• ​AA~

  • ​TWO PAIRS of angles from the triangles are congruent/the same

• ​SAS~

  • ​One angle is congruent to an angle on the other triangle

  • ​The sides on either side of the angle known have same scale factor

• ​SSS~

  • All 3 pairs of sides have same scale factor

Multiple Choice

Name the similar triangles

$$\Delta ABC\ \sim\ \Delta?$$  

• FED

• DEF

• EFD

• DFE

Multiple Choice

Are the triangles similar?

• Yes, by AA similarity

• No

• Cannot tell

Multiple Choice

Name the similar triangles

$$\Delta ABC\ \sim\ \Delta?$$  

• DBE

• BED

• DEB

• BDE

• EDB

Multiple Choice

Are the two triangle similar?

• Yes, by AA similarity

• No

• Cannot tell

Multiple Choice

Name the similar triangles

$$\Delta XEF\ \sim\ \Delta?$$  

• XYZ

• YZX

• ZXY

• ZYX

Multiple Select

What are the three ways to prove triangles are similar?

• AA

• ASA

• SAS

• SSS

• SSA

Formative 8.3

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Homework