Unit 2 Dilations, Similarity, and Introducing Slope Review

What is Dilation?

• Dilation means to enlarge or reduce
• Dilation means to reflect on something
• Dilation means to like something
• Dilation means to make something different by making it smaller

Does the image show a Dilation?

• Yes
• No

Does the image show a dilation?

• Yes
• No

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)

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)

• 1/2
• 3/2
• 2
• 1

Dilate Point A by a scale factor of 1/2 with the origin as the center of dilation.

• (-4,-4)

• (-1,-4)

• (-1,-1)

• (-2,-2)

Definition: The figure after a transformation has occurred. 

• Pre-image
• Image
• Translation
• Reflection

Definition: The figure before a transformation has occurred. 

• Pre-image
• Image
• Translation
• Reflection

A scale factor of less than one means

• that the image will be an enlargement (larger copy) of the pre-image.

• That the image will be the same as the preimage.

• That you need to subtract that amount off  of each side.
• That the image will be a reduction (smaller copy) of the preimage.