Unit 4: Dilation and Similarity Review

Use the similarity statement to set up a proportion. Then solve for x.

• 5

• 9

• 8

• 2

The center of dilation is at the origin. What is the scale factor?

• 2

• 3

• $\frac{1}{2}$

• $\frac{1}{3}$

The blue triangle is the preimage. The red triangle is the image. What is the scale factor?

• 2

• 3

• $\frac{1}{2}$

• $\frac{1}{3}$

Choose the Triangle Similarity Theorem you will test. Then decide if the triangles are similar or NOT similar.

• SAS

• SSS

• AA

• Similar

• Not similar

D, E, and F are all midpoints. Select all true statements.

•  $2\left(DE\right)=BC$  

•  $\frac{1}{2}\left(AC\right)=DF$  

•  $DF=DE$  

•  $AB=EF$  

•  $DE=FC$  

If two figures are similar their angles are______.

• proportional
• congruent
• supplementary
• complementary

Why are the triangles similar?

• AA

• SAS

• SSS

• Not similar

If the triangles are similar, state how.

• AA

• SAS

• SSS

• Not similar

If the triangles are similar, state why.

• AA

• SAS

• SSS

• Not similar

Are these triangles similar?
Known angles in Triangle 1:  40⁰,60⁰
Known angles in Triangle 2:  80⁰,40⁰

• Yes
• No
• There is not enough information to decide.