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Lesson 9.9 Line Reflections and Symmetry. Line of Symmetry. Divides the figure in two congruent halves. Rule for Line Reflection Over Y-axis . (-x, y). Rule for Line Reflection over x-axis. (x,-y). Line Reflections. y. A. C. B. x.
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Line of Symmetry • Divides the figure in two congruent halves.
Line Reflections y A C B x Line Reflection - Reflection occurs when points are redrawn across a line of symmetry at equal distance. Coordinate Notation “Opposite of” x y -x y -5 4 5 4 -5 1 5 1 -1 1 1 1 Reflect over Y-AXIS (-x, y) – opposite of x Reflect over X-AXIS (x, -y) – opposite of y
y x 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? Coordinate Notation L M N
Homework Page 487 (8-19) all