Dilations

Dilate the figure by a scale factor of 3 with the origin as the center of dilation. What are the coordinates of the image?
A(3,3) B(6,6) C(9,3)

• A'(9,9) B'(18,18) C'(27,9)

• A'(6,6) B'(9,9) C'(12,6)

• A'(0,0) B'(3,3) C'(6,0)

• A'(1,1) B'(2,2) C'(3,1)

Tell whether the transformation is a dilation. Explain.

• No, scale factor isn't the same.

• Yes, scale factor is the same.

A triangle has vertices with coordinates (2,0), (3, -1) and (-2,-5). If the triangle is dilated by a scale factor of 3 with the origin as the center of dilation, what are the coordinates of the vertices of the image?

• (5,3), (6,2), (1,-2)

• (6,0), (9,-3), (-6,-15)

• (2/3,0), (1,-1/3), (-2/3,-5/3)

• (-1,-3), (0,-4), (-5,-8)

The __________ is the ratio of a length of the new figure to the corresponding length on the original figure.

• reduction

• enlargement

• scale factor

• center of dilation

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)

The point (8, 12) was dilated to become point (2, 3). What was the scale factor?

• ½

• ¼

• 4

• 2

Dilate Point B by a scale factor of 1/2

• (1.5,-4)

• (-1.5,1)

• (-1,-1.5)

• (-2,-2)

The red triangle has been dilated by a scale factor of 1/4, which triangle is it's new image? 

• green triangle 

• red triangle 

• black triangle

• none of these 

A scale factor of less than one means

• that the image will be larger than the pre-image.

• That the image will be the same as the pre-image.

• That you need to subtract that amount off  of each side.

• That the image will be a reduction of the pre-image.

What is the definition of dilations ,in mathematical terms?

• to make larger or smaller

• to make larger

• none of the above

• to make smaller