1. 1.8 Glide Reflections and Compositions Warm Up Determine the coordinates of the image of P(4, –7) under each transformation. 1. a translation 3 units left and 1 unit up P1 2. a rotation of 90° about the origin P2 3. a reflection across the y-axis P3

2. 1.8 Glide Reflections and Compositions Warm Up Determine the coordinates of the image of P(4, –7) under each transformation. 1. a translation 3 units left and 1 unit up P1 2. a rotation of 90° about the origin P2 3. a reflection across the y-axis P3

3. Identify and draw compositions of transformations, such as glide reflections. Objectives 1.8 Glide Reflections and Compositions

4. composition of transformations is one transformation followed by ___________. glide reflection is the composition of a __________ and a __________ across a line parallel to the translation vector. translation reflection another

6. K L M L” M” K” M’ K’ L’ Example 1 Describe the composition in the diagram.

7. K L M M’ K’ L’ L” M” K” Rotate ∆KLM 180° about the origin and then reflect it across the y-axis. Example 2 Describe the composition in the diagram.

8. L KJ L'’ K’ J’ J” K” L' Example 3 Describe the composition in the diagram.

10. Example 5 ∆KLM has vertices K(4, –1), L(5, –2), and M(1, –4). Reflect it across the y-axis and then translate it (x, y)→(x + 2, y + 5).

11. Example 6 ∆JKL has vertices J(1,–2), K(4, –2), and L(3, 0). Reflect ∆JKL across the x-axis and then rotate it 180° about the origin.