GM-U3.1a Lesson: Reflections

Unit 3: Lesson 1a:
Reflections

Goal:

Students are going to graph and establish rules for reflections.

Concept:

​Reflection

A flip, a mirror image of the shape. An image will reflect through a line, known as the line of reflection. Every point in a figure is equidistant from each corresponding point in another figure.

​Procedure:

1) Over the x-axis: (x, y) ----> (x, -y)
2) Over the y-axis: (x, y) ----> (-x, y)
3) Over the line y=x: (x, y) ----> (-x, -y)
4) Over the line y=-x: (x, y) ----> (-y, -x)
5) Any y=? or x=?, make sure points are equidistant from line of reflection.

What is the line of reflection?

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​Example 1:

What is the line of reflection?

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​Example 2:

Reflect across the y-axis.
What the the coordiantes of the new image?

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​Example 3: