4.5 Dilations

Which of the following is a helpful way to find the scale factor?

• 
  

  $\frac{image}{preimage}$

• $\frac{preimage}{image}$

• $image\cdot preimage$

• $preimage\cdot image$

A dilation with scale factor greater than 1 creates a(n)

• Reduction

• Enlargement

The point B(6, 9) is dilated by a scale factor of 1/3. What is the location of B'?

• B' (18, 27)

• B' (3, 2)

• B' (2, 3)

• B' (9, 6)

The point C(4, 12) is dilated to the point A'(16,48). What is the scale factor?

• 1/4

• 4

• 16

• 1

In the following dilation from figure A to figure B, what is the scale factor?

• 1/3

• 3

• 1/2

• 2

In the following dilation from figure A to figure B, what is the scale factor?

• 2/5

• 3

• 1/2

• 5/2

When dilating a figure, it is important to scale each side by the same amount.

• True

• False

ABCD is dilated by a scale factor of 3 to create A'B'C'D'. If AB=6, what is A'B'?

• 2

• 9

• 18

• 3

ABCD is dilated by a scale factor of 1/2 to create A'B'C'D'. If A'B'=16, what is AB?

• 14

• 32

• 8

• 4

Which of the following expressions describes the ratio of the areas of two dilated figures with scale factor k?

• $k^2$

• $k$
  

• 1

• $\frac{1}{k}$