Dilations

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)

Choose the correct scale factor:

• 2
• 3
• 1/3
• 1/2

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

• ½
• ¼
• 4
• 2

A dilation is which of the following: 

• only an enlargement
• only a reduction
• Either an enlargement or a reduction
• Neither an enlargement or a reduction

State the coordinate of the image of the given point B (4,9) under a dilation with center at the origin with the given scale factor k = 2.

• (2,4.5)
• (-8,-18)
• (8,18)
• (9,4)

How do you write the algebraic notation when the scale factor is 3?

• (x, y) goes to (1/3x, 1/3y)

• (x, y) goes to (-3x, -3y)

• (x, y) goes to (x + 3, y + 3)

• (x, y) goes to (3x, 3y)

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)

Are these figures similar?

• yes
• no

The pair of figures is similar. Find the missing side.

• x = 20
• x = 12
• x = 5
• x = 4