1. Lesson 9.9 Line Reflections and Symmetry

2. Line of Symmetry Divides the figure in two congruent halves.

3. Rule for Line Reflection Over Y-axis (-x, y)

4. Rule for Line Reflection over x-axis (x,-y)

5. y x A B C Coordinate Notation Line Reflections Line Reflection - Reflection occurs when points are redrawn across a line of symmetry at equal distance. xy -54 1 1 -xy 54 51 11 “Opposite of” Reflect over Y-AXIS (-x, y) – opposite of x Reflect over X-AXIS (x, -y) – opposite of y

6. Points L(-3,2), M(3,1), and N(-2,-2) are the vertices of a triangle. If LMN is reflected over the x-axis, what are the coordinates of its image? y x L M N Coordinate Notation

7. Homework Page 487 (8-19) all