Introduction 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.

Tell whether each 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)

Dilate Point B by a scale factor of 3:

• (12,0)
• (12,12)
• (4,3)
• (0,12)

Similar figures have the same ______ but different ______. 

• measure; shapes
• sizes; shapes
• value; measures
• shape; sizes