Section 7.2 Reflections OBJECTIVE: To find reflection images of figures BIG IDEAS: Transformations and Coordinate Geometry ESSENTIAL UNDERSTANDING: When you reflect a figure across a line, each point of the figure goes to another point the same distance from the line, but on the other side. MATHEMATICAL PRACTICE: Make sense of problems and persevere in solving them

Reflection across a Line A Reflection ( ) across a line m, called the line of reflection, is a transformation with the following properties: If a point A is on line m, then the image of A is itself (that is ) If a point B is not on line m, then m is the perpendicular bisector of When you reflect a figure the shapes have opposite orientations but are equidistant from the line.

Properties of Reflections Reflections preserve ____________________ Reflections preserve _______________ measure Reflections ____________ each point of the _______________ to one and only one corresponding point of its _______________ Reflections are _______________motions and _______________

EX 1: Find the coordinates of the image b) c) d) e) f)

Reflection Rules Reflections in the coordinate axes have the following properties: If is reflected in the x-axis, its image is the point If is reflected in the y-axis, its image is the point   If is reflected in the line , its image is the point the same units above or below or left or right of the line, respectively If is reflected in the line , image is the point

EX 2: Find the coordinates of the image of the triangle a) Graph points . Graph the coordinates of

EX 2: Find the coordinates of the image of the triangle b) Graph points . Graph the coordinates of

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