# What is the scale factor of the dilation?

Under a dilation, the point (6, 18) is moved to (3, 9). What is the scale factor of the dilation?

`````` a  0.2

b  0.5

c  2.0

d  3.0 ``````

Triangle ABC has vertices at (-1, 3), (2, 1), and (-2, -1). Using triangle ABC as the pre-image and the origin as the center of dilation, which of the following is not a coordinate of a dilation that uses a scale factor of 4?

``````  a  (4, 12)

b  (-4, 12)

c  (8, 4)

d  (-8, -4)``````

T ɾąքҽ zoid ABCD has vertices at (-3, -3), (-3, 4), (-5, 3), and (-5, -1). Using t ɾąքҽ zoid ABCD as the pre-image and the origin as the center of dilation, what are the coordinates of a dilation that uses a scale factor of -2?

`````` a   (-6, -6), (-6, 8), (-10, 6), and (-10, -2)

b   (-3/2, 3/2), (-3/2, 2), (-5/2, 3/2), and (-5/2, -1/2)

c   (3/2, -3/2), (3/2, -2), (5/2, -3/2), and (5/2, 1/2)

d   (6, 6), (6, -8), (10, -6), and (10, 2) ``````

### `4 Answers`

• `1) B`

2)A

3)D

• < For my K12 fam >

1 – Under a dilation, the point (6, 18) is moved to (3,9). What is the scale factor of the dilation?

2 – Triangle ABC has vertices at (-1, 3), (2, 1) and (-2, -1). Using triangle ABC as the pre-image and the origin as the center of dilation, which coordinate point is not a coordinate of a dilation that uses a scale factor of 4?

3 – T ɾąքҽ zoid ABCD has vertices at (-3, -3), (-3, 4), (-5, 3), and (-5, -1). Using t ɾąքҽ zoid ABCD as the pre-image and the origin as the center of dilation, what are the coordinates of a dilation that uses a scale factor of -2?

Answer: (6, 6), (6, -8), (10, -6) and (10, 2)

4 – What is the scale factor used to create the dilation?