9 6 Dilations I can draw dilations in

9. 6: Dilations I can draw dilations in the coordinate plane.

If the images to the right describe a dilation, in your own words, define dilation:

Vocabulary! Dilations on a Coordinate Plane Scale Factor The ratio of a length on an image to a corresponding length on the preimage.

Example 1: Trapezoid EFGH has vertices E(– 8, 4), F(– 4, 8), G(8, 4) and H(– 4, – 8). Graph the image of EFGH after a dilation centered at the origin with a scale factor of 1/4.

Example 2 a: Find the image of each polygon with the given vertices after a dilation centered at the origin with the given scale factor. J(2, 4), K(4, 4), P(3, 2); r=2

Example 2 b: Find the image of each polygon with the given vertices after a dilation centered at the origin with the given scale factor. D(– 2, 0), G(0, 2), F(2, – 2) r= 1. 5

Example 3: Leila drew a polygon with coordinates (– 1, 2), (1, – 2), and (– 1, – 2). She then dilated the image and obtained another polygon with coordinates (– 6, 12), (6, – 12), and (– 6, – 12). What was the scale factor and center of this dilation?

Example 4: Find the scale factor from the pre-image to the image for the following dilation. A(2, 5), B(3, -1), C(4, 2) and A’(3, 7. 5), B’(4. 5, -1. 5), C‘(6, 3).

Summary! Nemo is located on the coordinate plane. Write down Nemo’s coordinate points here: Marlin believes Nemo will be 3 times the size he is now. Dilate the Nemo using a scale factor of 3. Write the coordinate points here: Graph the dilated coordinate points and name them accordingly. When you are finished, compare with your neighbor.

Homework: pg. 678, #15 – 17, 21, 26