Dilations and Similarity ESL

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

A scale factor of less than one but greater than zero means

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

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

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

• That the prime image will be a reduction of the preimage.

Definition: The figure before a transformation has occurred. 

• Pre-image
• Image
• Translation
• Reflection

Definition: The figure after a transformation has occurred. 

• Pre-image
• Image
• Translation
• Reflection

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

• reduction
• enlargement
• scale factor
• center of dilation

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)

Does the image show a dilation?

• Yes
• No

Does the image show a Dilation?

• Yes
• No

A triangle has vertices A(0,0), B(8,0), C(3,-2). Find the coordinates of the triangle after a dilation with a scale factor of  4. The dilation is (X,Y) --- (4x,4y)

• A(3,3), B(4,4), C(-3,-4)
• A(-4,8), B(6.5,8), C(7,7)
• A(0,0), B(32,0), C(12,-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)