Dilations Recap

Dilations preserve congruence. 

• True
• False

Dilations preserve orientation. 

• True
• False

A dilation with a scale factor less than 1 but greater than 0 is a(n) _____.

• Enlargement
• Reduction

If a triangle is dilated by a scale factor of 4, then the rule for the dilation would be _____.

• (x, y) → (x+4, y+4)
• (x, y) → (4x, 4y)
• (x, y) → (¼x, ¼y)
• (x, y) → (x-4, y-4)

If a figure is dilated by a scale factor of ¾, then the rule for the dilation would be _____.

• (x, y) → (x+¾, y+¾)
• (x, y) → (3x, 4y)
• (x, y) → (¾x, ¾y)
• (x, y) → (x-¾, y+¾)

• (x, y) → (⅓x, ⅓y)

• (x, y) → (x+6, y+6)

• (x, y) → (x+3, y+3)

• (x, y) → (3x, 3y)

Rectangle EFGH is dilated by the rule (x, y) → (2.5x, 2.5y).  If the coordinates for point E are (-6, 8), what is the location of point E'?

• (-3.5, 10.5)
• (2.5, 2.5)
• (-12, 16)
• (-15, 20)

Pentagon ABCDE is dilated to create Pentagon A'B'C'D'E'.  Point A is at (5, 2) and point A' is at (8, 3.2).  Which rule best describes this dilation?

• (x, y) → (8x, 3.2y)
• (x, y) → (0.625x, 0.625y)
• (x, y) → (x+3, y+1.2)
• (x, y) → (1.6x, 1.6y)

On a scale from 1-4, with 1 being the lowest and 5 being the highest, how do you feel about dilations on the coordinate plane?

• 1

• 2

• 3

• 4

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)