Scale Factor with Dilations

How do you write the algebraic notation when the scale factor is 1/2?

• (x, y) −> (2x, 2y)

• (x, y) −> (1/2x, 1/2y)

• (x, y) −> (-2x, -2y)

• (x, y) −> (2x, 1/2y)

Tags

CCSS.8.G.A.3

Find the scale factor of the dilation. Then tell whether the dilation is a reduction or an enlargement.

• 2 / 5; reduction

• 5 / 2; enlargement

• 2 / 3; reduction

• 3 / 2; enlargement

Tags

CCSS.8.G.A.3

If the scale factor is less than one, the new figure will be

• an enlargement

• a reduction

• a scale factor

• bigger

Tags

CCSS.8.G.A.3

If the scale factor is greater than one, the new figure will be

• a reduction

• an enlargement

• a scale

• not proportional

Tags

CCSS.8.G.A.3

Describe the similarity transformation that maps to (dilations have a center at the origin).

• a dilation with a scale factor of 2 followed by a translation 4 units right and 3 units down.

• a dilation with a scale factor of 1 / 2 followed by a translation 4 units left and 3 units up.

• Translation 4 units right and 3 units down followed by a dilation with a scale factor 2.

• Translation 4 units left and 3 units up followed by a dilation with a scale factor 1 / 2.

Tags

CCSS.HSG.SRT.A.2

CCSS.8.G.A.4

The two polygons are similar.

Find the value of x

Find the scale factor

Find the ratio of the perimeter.

Value of x: ____, Scale factor: ____, Ratio of perimeter: ____

Tags

CCSS.HSG.SRT.A.2

Are the two polygons similar? If not, explain why. (They are not drawn to scale, but you can assume all angles are 90°.)

• Yes

• No; Not enough information to tell

• No; 5 ⁄ 25 ≠ 6 ⁄ 10

• No; 5 ⁄ 25 ≠ 8 ⁄ 41

Tags

CCSS.HSG.SRT.B.5

If two polygons are SIMILAR, then the corresponding sides must be _____.

• Congruent

• Proportional

• Parallel

• similar

Tags

CCSS.8.G.A.2

CCSS.HSG.CO.B.6

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'(0,0) B'(3,3) C'(6,0)

• A'(1,1) B'(2,2) C'(3,1)

Tags

CCSS.8.G.A.3

If point is at N(-1, 2) and point is at N'(-2, 4), what scale factor was point N multiplied by?

• 2

• 3

• 1/3

• 1/2

Tags

CCSS.8.G.A.3