Dilating Lines Notes

Dilating point A using center C and scale factor 2.5 gives image A'. Dilating point B using center C and scale factor 2.5 gives image B'. What statements are true?

• Segment A'B' is 2.5 times as long as line segment AB.

• Line A'B' is not parallel Line AB.

• Line A'B' is parallel to line AB.

• There is not enough information.

Answer explanation

distance x scale factor means A'B' is 2.5 times larger

Dilations of lines NOT including the center point are parallel.

Dilating point A using center C and scale factor 2.5 gives image A'. Dilating point B using center C and scale factor 2.5 gives image B'. What is the length of segment A'B'?

Answer explanation

distance x scale factor

4 x 2.5 =

Quadrilateral NDPM was dilated to quadrilateral N'D'P'M'. What was the scale factor for this dilation?

• 2

• 3

• 1/3

• 1/2

Answer explanation

pre-image / image

What is the measure of angle A'B'C'?

• 40 degrees

• 75 degrees

• 45 degrees

• 60 degrees

Answer explanation

Angles do not change in dilations.

Corresponding angles in dilations are congruent.

What is the scale factor?

• 2.5

• 2

Answer explanation

line f is dilated with a scale factor of 2 to create g. Which point is the center of dilation?

• A

• B

• C

• D

Answer explanation

f is the pre-image. g is the image

Scale factor of 2 moves f father away from D.

A doesn't work because the scale factor would need to be 1/2

B or C don't work because the are ON the lines.

What is the scale factor?

Answer explanation

Polygon Q (image) is a scaled copy of Polygon P (pre-image). The scale factor is 0.75. If x is 6, what is y?

• 4.5

• 48

Answer explanation

Point B is dilated using Center A and a scale factor of 1/3. Which point is the IMAGE of B?

• A

• B

• C

• D

When you dilate you MULTIPLY the distance by the _____ _____