Dilations and Scale Factors

What is the definition of dilations in mathematical terms?

• to make larger or smaller

• to make larger

• none of the above

• to make smaller

A dilation produces a similar figure

• True

• False

If the scale factor is less than 1, the new figure will be

• an enlargement

• a reduction

• a scale factor

• bigger

What variable represents scale factor in the algebraic representation (x,y) to (kx,ky)?

• x

• y

• z

• k

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

State the coordinate of the image of the given point B (4,9) under a dilation with center at the origin with the given scale factor of 2.

• B' (2 , 4.5)

• B' (-8 ,-18)

• B' (8 ,18)

• B' (9 ,4)

Is this an enlargement or reduction? (blue = original image)

• reduction

• enlargement

Similar figures have the same ______ but different ______. 

• measure; shapes

• sizes; shapes

• value; measures

• shape; sizes

How do you write the algebraic notation when the scale factor is 1/2?

• (x, y) −> (2x, 2y)

• (x, y) −> (1/2x, 1/2y)

• (x, y) −> (-2x, -2y)

• (x, y) −> (2x, 1/2y)

Find the scale factor of the dilation. Then tell whether the dilation is a reduction or an enlargement.

• 2 / 5; reduction

• 5 / 2; enlargement

• 2 / 3; reduction

• 3 / 2; enlargement