Dilations on the Coordinate Plane (Handout & Homework)

To dilate a figure on the coordinate plane, multiply the x and y values of the each ordered pair by the given ​ (a)  

• scale factor
• ratio
• equation
• pre-image

If the scale factor is ​ (a)   than one, it will enlarge a figure.

• greater
• less
• equal

If the scale factor is ​​ (a)   than one, it will reduce a figure.

• less
• equal
• greater

When a dilation has occurred on the coordinate plane, you can find the scale factor by choosing corresponding sides or vertices and setting up a ratio:​ (a)  

Dilate triangle ABC using a scale factor of 1.5. Use the graph to answer the following questions.

1. 1. Record the pre-image coordinates

• A (-2,-2)

  B (2, 2)

  C (4, -2)

• A (2, -2)

  B (-2, 2)

  C (-4, -2)

• A (-2, -2)

  B (2, 2)

  C (-2, 4)

Dilate triangle ABC using a scale factor of 1.5. Use the graph to answer the following questions.

1. 1. Record the image coordinates

• A' (-3, -4)

  B' (3, 5)

  C'(-3, 6)

• A' (-3, -3)

  B' (3, 3)

  C' (6,-3)

• A (-2, -2)

  B (2, 2)

  C (-2, 4)

Graph the image.

The triangle dilated by a scale factor of 1.5

Write a rule to represent the dilation.

Find the scale factor that was used in the dilation and write the rule to represent the dilation.

Find the scale factor that was used in the dilation and write the rule to represent the dilation.