Similar Triangles Quiz Review

Two objects that are the same shape but not the same size are _______.

• Congruent
• Vertical
• Similar
• Complementary 

All angles in similar figures are congruent.

• True

• False

Answer explanation

True! The angles don't change even though the figures get larger/smaller.

Corresponding sides in similar figures must be proportional.

• True

• False

Answer explanation

True! All the ratios of corresponding sides must have the same scale factor.

For two figures to be similar, sides must be_____________and angles must be _____________________.

• congruent, proportional
• congruent, congruent
• proportional, proportional
• proportional, congruent

Determine whether the triangles are similar by AA~, SSS~, SAS~, or not similar.

• AA

• SSS

• SAS

• no similar

Answer explanation

m<E = 106 and m<F = 45, so you have 3 sets of congruent, corresponding angles. You need ATLEAST 2 for AA~.

Determine whether the triangles are similar by AA~, SSS~, SAS~, or not similar.

• SSS

• AA

• SAS

• not similar

Answer explanation

Check the scale factors of the corresponding sides.

48/60 and 56/70

Find the two vertical angles.

SAS~

Are the triangles similar?

• Yes
• No

Find missing side.

• 5

• 7

• 9

• 11

Answer explanation

 $\frac{6}{18}=\frac{x}{21}$  

Determine if the triangles are similar. Justify.

• Yes, by SSS.
• Yes, by SAS. Scale Factor is 1:2.
• Yes, by SAS. Scale Factor is 3:1.
• No, not similar.

Choose the similarity statement for the triangles.

• ΔMNL ∼ ΔOPQ
• ΔNOM ∼ ΔPQL
• ΔLMN ∼ ΔPQO
• ΔMLN ∼ ΔPQO