Types of Reflections
There are many different types of reflections and reflections can happen across just about any line, even diagonals. In 7th grade, the only 2 reflections you will have to deal with are reflections across the x-axis and reflections across the y-axis. Both of these reflections have fairly simple rules.
Reflections across the x-axis:
![Picture](/uploads/2/0/1/1/20114429/5754683.png?285)
Reflecting across the x-axis means that the figure in question simply flips over the line made by the axis. In doing so, it is exactly as far away from the axis on the other side as it was on the original side. The figure to the left is a good example.
Point B was originally 4 units above the x-axis. When if flips over the x-axis, it is now 4 units below, the same distance away.
One good rule to change points when reflecting across the x-axis is to change the signs of all the y-coordinates. For instance, using the figure to the left:
A (-2 , 1) --> change the sign on the y-coordinate --> A' (-2 , -1)
When reflecting across the x-axis, ONLY change the sign of the y-coordinate.
Point B was originally 4 units above the x-axis. When if flips over the x-axis, it is now 4 units below, the same distance away.
One good rule to change points when reflecting across the x-axis is to change the signs of all the y-coordinates. For instance, using the figure to the left:
A (-2 , 1) --> change the sign on the y-coordinate --> A' (-2 , -1)
When reflecting across the x-axis, ONLY change the sign of the y-coordinate.
Reflections across the y-axis:
![Picture](/uploads/2/0/1/1/20114429/8119744.jpg)
Reflecting across the y-axis means that the figure in question simply flips over
the line made by the axis. In doing so, it is exactly as far away from the axis
on the other side as it was on the original side. The figure to the left is a
good example.
Point A was exactly 7 units away from the y-axis before the reflection and A' is exactly 7 units away from the y-axis on the other side.
A good rule to change points when reflecting across the y-axis is to change the sings of all the x-coordinates. The figure to the left demonstrates this using the numbers circled in red.
A (-7 , -6) --> change the sign on the x-coordinate --> A' (7 , -6)
When reflecting across the y-axis, ONLY change the sign of the x-coordinate.
the line made by the axis. In doing so, it is exactly as far away from the axis
on the other side as it was on the original side. The figure to the left is a
good example.
Point A was exactly 7 units away from the y-axis before the reflection and A' is exactly 7 units away from the y-axis on the other side.
A good rule to change points when reflecting across the y-axis is to change the sings of all the x-coordinates. The figure to the left demonstrates this using the numbers circled in red.
A (-7 , -6) --> change the sign on the x-coordinate --> A' (7 , -6)
When reflecting across the y-axis, ONLY change the sign of the x-coordinate.