Dilations Centered at the Origin

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.

What is the scale factor of this dilation?

True or false, when a figure is dilated, the corresponding angles are congruent?

• True

• False

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

• reduction

• enlargement

• scale factor

• center of dilation

True or false, when a figure is dilated, the new perimeter is always greater?

• True

• False

Quad OBCD is similar to Quad OHTE because:

• Quad OBCD can be reflected over the x axis and then rotated 90 degrees

• Quad OBCD can be reflected over the x-axis and then dilated about point O by a scale factor of 2.

• Quad OBCD can be reflected over the y-axis and then dilated about point O by a scale factor of 2.

• Quad OBCD can be reflected over the y-axis and then dilated about point O by a scale factor of 1/2.

ΔOBC is similar to ΔOGT because: (choose the best answer)

• ΔOBC can be dilated about point O by a scale factor of 1/2, and then rotated 90 degrees about point O.

• ΔOBC can be dilated about point G by a scale factor of 1/2, and then reflected over the x- axis

• They aren't similar

• They map to each other with similarity transformations.

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

• 1/7

• 4/5

• 5/4

• 7

 A dilation can produce a larger figure or a(n)______

• reduction

• enlargement

• scale factor

• center of dilation

The line whose equation is 3x – 5y = 4 is dilated by a scale factor of 5/3 centered at the origin. Which statement is correct?

• The image of the line has the same slope as the pre-image but a different y-intercept.

• The image of the line has the same y-intercept as the pre-image but a different slope.

• The image of the line has the same slope and the same y-intercept

  as the pre-image.

• The image of the line has a different slope and a different y-intercept from the pre-image.