Reflecting a point about a line

Construction

1) Create a point A. 2) Reflect point A about the x-axis 3) Label the reflection point A' (right click on the point and choose 'Rename'). Next... 4) Create a point B at (1,2) and change the color of the point to red under the style bar 5) Reflect point B about the line y=x and change the color of the point to red under the style bar. 6) Label the reflection point B' (right click on the point and choose 'Rename'). Finally... 7) Create a point C on the line y=x and change the points color.

Reflection about lines

Question 1

What is the coordinate for A'?

Question 2

What is the coordinate for B'?

Question 3

What do you notice about the distance from point B to the line of reflection and the distance from point B' to the line of reflection? Do you think this observation holds true for all reflections of a point?

Question 4

What happens if you reflect point C about the line it is on?

8^th grade Geometry:Understand congruence and similarity using physical models, transparencies, or geometry software.CCSS.MATH.CONTENT.8.G.A.1 Verify experimentally the properties of rotations, reflections, and translations