Dilations Transformations of Triangles

If the scale factor of a dilation is greater than 1 then we know it is a __________________.

• reduction

• reflection

• enlargement

• target

A dilation will produce an image that is similar to the pre-image.

• True

• False

Triangle ABC is obtained by a dilation of triangle LMN with the origin as the center of dilation by a scale factor of 2 followed by a reflection over the y-axis. What is true?

• Triangle ABC is similar and congruent to triangle LMN.

• Triangle ABC is similar but no congruent to triangle LMN.

• Triangle ABC is congruent but not similar to triangle LMN.

• Triangle ABC is neither similar nor congruent to triangle LMN.

The scale factor of 1 will produce a congruent figure.

• True

• False

A figure with coordinates (-8,-4), (-6,4), (5, 7), (9,-3) is dilated with a scale factor of 3 with the origin as the center of dilation. Which points represent one of the coordinates of the figure after the dilation?

• (-24, 12)

• (15,-21)

• (30,12)

• (-18,12)

One vertex of a triangle is point M (5,7). The triangle is dilated about the origin by a scale factor of 2. What are the coordinates of point M'?

• (7,9)

• (-10,-14)

• (10,14)

• (10,16)

An image is dilated about the origin with a dilation of 1/2. What best explains the pre-image and the image?

• The image of the polygon has congruent side lengths and angle measures.

• The image of the polygon has congruent side lengths but not congruent angle measures.

• The image of the polygon has congruent angle measures but not congruent side lengths.

• The image of the polygon does not have congruent side lengths or angle measures.

A figure undergoes a sequence of transformations that results in a figure that is similar but not congruent to the pre-image. Which could be the sequence of transformations?

• A dilation by a scale factor of 3, then a reflection over the y-axis.

• A reflection over the x-axis then a translation of 2 units left and 4 unit down.

• A rotation of 90 degrees clockwise and a reflection across the y-axis

• A translation of 2 units right and 6 units up then a 270 degree rotation.

A rectangle undergoes a single transformation that results in an image that is similar but not congruent to the original triangle. Which single transformation could be used to create the similar image that is not congruent to the original triangle?

• reflection

• dilation

• rotation

• Any of these could be the transformation.

One vertex of a triangle is point J (9,4). The triangle is dilated by a scale factor of 5. The center of the dilation is the origin.

Which statement is true?

• The new triangle is both similar to and congruent to the original triangle.

• The new triangle is similar but not congruent to the original triangle.

• The new triangle is congruent but not similar to the original triangle.

• The new triangle is neither congruent not similar to the original triangle.