9.3 Perform Reflections P 580 With row partners

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9.3 Perform Reflections P 580 With row partners Must complete STEPS 1,2 and 3 Must answer DRAW CONCLUSIONS questions 1-5 Have 15 minutes to finish.

Vocab Reflection – a transformation that uses a line like a mirror to reflect an image. Line of reflection – the mirrored line THEOREM 9.2 Reflection Theorem – a reflection is an isometry

Graphing reflections The vertices of ABC are A(2,4), B(6,3) and C(3,2). Graph the reflection of ABC described. In the line n: x=1

Graphing reflections The vertices of ABC are A(2,4), B(6,3) and C(3,2). Graph the reflection of ABC described. In the line n: x=1

Graphing reflections The vertices of ABC are A(2,4), B(6,3) and C(3,2). Graph the reflection of ABC described. In the line n: x=1 In the line m: y=3

Graphing reflections The vertices of ABC are A(2,4), B(6,3) and C(3,2). Graph the reflection of ABC described. y = 5

Graphing reflections The vertices of ABC are A(2,4), B(6,3) and C(3,2). Graph the reflection of ABC described. y = 5 x = -2

Graphing reflections The vertices of ABC are A(2,4), B(6,3) and C(3,2). Graph the reflection of ABC described. y = 5 x = -2 y = -1

More reflections The endpoints of FG are F(-2,1) and G(2,3). Reflect the segment in the line y = x. Graph FG and its image.

Coordinate Rules for Reflections If (a,b) is reflected in the x-axis, its image is the point (a,-b). If (a,b) is reflected in the y-axis, its image is the point (-a,b) If (a,b) is reflected in the line y = x, its image is the point (b,a) If (a,b) is reflected in the line y = -x, its image is the point (-b, -a)

Graph one more reflection y = -x Graph ABC with vertices A(1,3), B(4,4), and C(3,1). Reflect ABC in the lines y = -x.

Using matrix multiplcation You can use a matrix to find the reflection in the x and y axis. Write the reflection matrix to the LEFT of the polygon matrix, then multiply. Reflection in the x-axis 1 0 0 −1 Reflection in the y-axis −1 0 0 1

Matrix Mr. Anderson The vertices of DEF are D(2,3), E(4,4) and F(5,1). Find the reflection of DEF in the y-axis using matrix multiplication. Graph DEF and its image.