Introduction to Similarity

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

• Congruent

• Vertical

• Similar

• Complementary 

Are the triangles similar?

• Yes

• No

All angles in similar figures are congruent.  

• True

• False

Sides in similar figures must be proportional.  

• True

• False 

In order for two polygons to be similar, what must be true about the sides and angles?

• All sides and angles are congruent

• All sides and angles are proportional

• Sides are congruent, Angles are proportional

• Sides and proportional, Angles are congruent

Are the triangles similar?

• Yes

• No

The following triangles are similar.
AC ∼

•  DF

• AB 

•  ED

•  FC

Which triangle is similar to the above triangle ?

• A

• B

• C

• D

Are the following similar? Why or why not?

• Yes

• No, the corresponding angles are not equal.

• No, the ratios of the corresponding sides are not equal.

Tell whether the two figures are similar. Explain your reasoning.

• Yes, similar because they are the same shape and side lengths are proportional.

• No, not similar because they are the same shape, but side lengths are not proportional.

• Yes, same shape

• No, different sizes