Dilations Through the Origin

Point B (-10,-6) is dilated with a scale factor of 1/2 and the center of dilation at the origin. What are the coordinated of B'?

• (5,3)

• (20,12)

• (-20,-12)

• (-5,-3)

A square with a perimeter of 20 units is graphed on a coordinate grid. The square is dilated by a scale factor of 0.4 with the origin as the center of dilation. If (x, y) represents the location of any point on the original square, which ordered pair represents the coordinates of the corresponding point on the resulting square?

• (20x, 20y)

• (0.4x, 0.4y)

• (x+20, y+20)

• (x+0.4, y+0.4)

A polygon will be dilated on a coordinate grid to create a larger polygon. The polygon is dilated using the origin as the center of dilation.
Which rule could represent this dilation? 

• (x,y) → (0.5 − x,0.5 − y) 

• (x,y) → (x−7,y−7) 

• (x, y) → (0.9x, 0.9y)

Choose the correct scale factor:

• 2.5

• 1.5

• 3.5

• 4

The blue shape is a dilation of the black shape. Is it an enlargement or a reduction?

• Enlargement

• Reduction

Given A and A', find the scale factor you may assume the center of dilation is the origin. A (22, -7), A' (11, -3.5)

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

• (x, y) --> (1/3x, 1/3y)

• (x, y) --> (-3x, -3y)

• (x, y) --> (x + 3, y + 3)

• (x, y) --> (3x, 3y)

Gabriela draws ABCD. Next she dilates ABCD by a scale factor of 3. What is the ordered pair for B'?

Triangle ABC has vertices A (-2, 2), B (2, 4) and C (3, -1).  What are the coordinates of A' after a dilation by a scale factor of 2.5?

• (-5, 5)

• (5, -5)

• (5, 10)

• (7.5, -2.5)

What is a Center of Dilation?

• The capital of Mathmagical Land

• Another word for scale factor

• A fixed point that doesn't change when a shape enlarges or shrinks

• Another word for the origin