Dilations and Similarity ESL

Let triangle XYZ be the dilated image of triangle ABC with a scale factor of k = 3. Which of the following is the correct center of dilation?

• (0, 0)

• (4, 1)

• (-5, 5)

• (1, 4)

The pair of figures is similar. Find the missing side.

• x = 9

• x = 28

• x = 7

• x = 63

The triangles are similar, solve for the question mark.

• 8

• 12.5

• 18

• 24

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.

• A

• B

• C

• D

Which of the statements is true about the graphed triangles?

• They are similar, because one can be obtained by dilating the other about the origin with a scale factor of 2.

• They are similar, because one can be obtained by dilating the other about the origin with a scale factor of 1/2.

• They are not similar, because one can be obtained by dilating the other about the origin with a scale factor of 2.

• They are not similar, because one can be obtained by dilating the other about the origin with a scale factor of 1/2.

Even though the size of the image changed, which statement below explains why this is NOT an example of a dilation? (NOT similar figures)

• the width increased in size, but the height did not change at all (they must change the same way)

• the width of the image got larger, not smaller

• this is a dilation actually, because the image increased 3 times the original size

• these are not a dilation, because the two images are congruent

Does the rule (x, y) --> (5x, 5y) produce a similar, congruent, or neither image

• Similar with a SF of 5

• Congruent

• Neither

What is the value of X?

• X=4

• X=6

• X=3

• X=2

How does a dilation change the angles of a polygon?

• It changes by the scale factor.

• Dilations do not change the angles.

• It is impossible to answer this question.  The angles change unpredictably.

• The angles all change to larger angles.