Dilations and Similar Polygons

Triangle ABC is dilated so that the coordinates of C' are (2, -1).  What was the scale factor of the dilation?

• 3

• 2

• 1/2

• 1/3

Polygon ABCDE will be dilated by a scale factor of 2.  Which statement is NOT true of the dilation?

• The corresponding angles of the two polygons will be equal.

• The dilation will be an enlargement.

• The original and the image will be congruent.

• Polygon A'B'C'D'E' will be proportional to polygon ABCDE. 

In a dilation what mathematical operation is used with the scale factor?

• addition 

• subtraction 

• multiplication 

• division 

The two rectangles are scale drawings. What is the measurement of x?

• 21

• 1.25

• 20

• 4

A dilation is which of the following: 

• only an enlargement

• only a reduction

• Either an enlargement or a reduction

• Neither an enlargement or a reduction

A dilation produces a similar figure

• True

• False

When a dilation has a scale factor greater than one, the dilation is an enlargement.

• True

• False

When the scale factor of a dilation is less than one, the dilation is a reduction.

• True

• False

Enlargement or reduction?  Find the scale factor!

• It's a reduction; the scale factor is 2.

• It's an enlargement; the scale factor is 2.

• It's an enlargement; the scale factor is 1/2.

• It's a reduction; the scale factor is 1/2.

The original perimeter of a rectangle is 30cm, if we enlarge it by a scale factor of 4 what is the new perimeter?

• 120

• 480

• 1920