Similarity and Dilations Review

• a

• b

• c

• d

Answer explanation

1/2 = 0.5

a) 0.4 is smaller than 0.5

b) 0.5 is = to 0.5

c) 1/4 is equal to 0.25. 0.25 is smaller than 0.5

• 36

• 144

• 18

• 9

Answer explanation

If we see a dilation AND the scale factor....MULTIPLY. Dilations= multiplication.

Take the area, 36, and multiply by 1/2.

• a

• b

• c

• d

Answer explanation

Make sure to write down your triangle names and stack them.

ABC

FGH

This is your cheat code

• 4

• 2

• 1/2

• 1/4

Answer explanation

To find the scale factor, choose any point. Then set up new over original

New

Original

• a

• b

• c

• d

Answer explanation

Make sure to write your triangle names and STACK them.

GHF

JHK

• (0 , 4)

• (0, 16)

• (4 , 16)

• (16 , 0)

Answer explanation

Take the ordered pairs and multiply it by the scale factor, 4.

Example:

A (0 , 4)

0x4=0

4x4=16

A' (0 , 16)

Which of the following do not preserve congruence?

• reflections

• translations

• rotations

• dilations

Answer explanation

Dilations change size so they do not stay the same size...aka they do not preserve their size or congruence.

Which of the following do preserve congruence?

• reflections

• translations

• rotations

• dilations

Kimberly wants to reduce the size of the triangle A'B'C' proportionally. Which transformation should she choose?

• reflection

• translation

• rotation

• dilation

A 40 foot tall flagpole casts a shadow that is 8 feet long. Find the length, in feet, of a shadow cast by a nearby man who is 6 feet tall.

Answer explanation

Make sure to draw the situation. Label the sides.

Set up your proportion.

Cross multiply and then divide.