Dilations and Similar Triangles

Choose the correct scale factor:

• 2

• 3

• 1/3

• 1/2

Figure D´E´F´G´ is a dilation with center (0, 0) of figure DEFG. What is the scale factor?

Find the value of x, and use it to find KM.

• x = 10, KM = 25

• x = 11, KM = 28

• x = 13.3 KM = 34.9

• x = 4.3, KM = 8

A dilation always produces a similar figure. Similar figures have the same ______ but different ______. 

• measure; shapes

• sizes; shapes

• value; measures

• shape; sizes

Which must be true of a scale factor of a dilation if the image is smaller that the pre-image?

• The scale factor is positive

• The scale factor is greater than 1

• The scale factor is between 0 and 1

• The scale factor is negative

State the coordinate of the image of the given point B (-10,-6) under a dilation with center at the origin with the given scale factor k = 1/2.

• (5,3)

• (20,12)

• (-20,-12)

• (-5,-3)

Rectangle ABCD is dilated by a scale factor of 1/2 with the center at B. What are the coordinates of point D?

• (6,4)

• (3,2)

• (4,7)

• (12,8)

Determine whether the triangles are similar by AA~, SSS~, SAS~, or not similar.

• AA

• SSS

• SAS

• Not similar

Determine whether the triangles are similar by AA~, SSS~, SAS~, or not similar.

• AA

• SSS

• SAS

• no similar

Determine whether the triangles are similar by AA~, SSS~, SAS~, or not similar.

• SSS

• AA

• SAS

• not similar