Dilations and Perimeter

If a shape is dilated by a scale factor of one-half, what is the resulting perimeter? 

• The same as the perimeter of the preimage

• The new perimeter is bigger than the preimage

• The new perimeter is smaller than the preimage

• The new perimeter is 4 times the original

What is the scale factor from ABCD to MNOP?

• 2/3

• 3/2

• 2

• 3

Dilate the figure by a scale factor of 3 with the origin as the center of dilation. What are the coordinates of the image?

• A'(9,9) B'(18,18) C'(27,9)

• A'(6,6) B'(9,9) C'(12,6)

• A'(9,9) B'(3,3) C'(6,0)

• A'(1,1) B'(2,2) C'(3,1)

A scale factor of less than one means

• that the image will be larger than the pre-image.

• That the image will be the same as the pre-image.

• That you need to subtract that amount off  of each side.

• That the image will be a reduction of the pre-image.

Choose the correct scale factor:

• 2

• 3

• 1/3

• 1/2

The __________ is the ratio of a length of the new figure to the corresponding length on the original figure.

• reduction

• enlargement

• scale factor

• center of dilation

In a dilation what mathematical operation is used with the scale factor?

• addition 

• subtraction 

• multiplication 

• division 

You can map PQRS to TUVW by first doing a reflection and then a dilation. What is the dilation?

• (x,y) -> (3x, 3y)

• (x,y) -> (1/3x,1/3y)

• (x,y) -> (2x, 2y)

• (x,y) -> (1/2x, 1/2y)

Triangle ABC is dilated using a scale factor of 1/2. What are the new coordinates of point A'?

• (-3, 3)

• (-12, 12)

• (-2, 2)

Square A is a Dilation of Square B. What is the scale factor of the squares?

• 1/7

• 4/5

• 5/4

• 7