# How to do a reflection in math

Reflections - Corbettmaths

Reflections review. Math Basic geometry Transformations, congruence, and similarity Reflections. So this is going to be our C here.

## Reflections: How to reflect a point

Now C prime would have the same X coordinate but instead of being four units below the X axis, it will be four units above the X axis. So let's make this right over here A, A prime. When you reflect a point across the x -axis, the x- coordinate remains the same, but the y -coordinate is transformed into its opposite its sign is changed. Imagine a straight line connecting A to A' where the origin is the midpoint of the segment.

Reflections in the coordinate plane: When we're talking about transformations, there are 4 different types one of which is a reflection. What this one does, it takes every x coordinate and then makes that into a y coordinate and does the same for your y coordinates, every y coordinate becomes an x coordinate so if we have a, our a since we have a prime and a double prime our a triple prime is going to be at 5, 3 so what I'm going to do is I'm going to write 3, 5 right here. Problem 2 What is the image of point A 31,1 after reflecting it across the x-axis. So, its image, A prime we could say, would be four units below the X axis. Next Unit Area. R is an invariant point in the above. Video transcript - [Instructor] We're asked to plot the image of quadrilateral ABCD so that's this blue quadrilateral here. What is Reflection? Now let's make this our C.

## Reflecting shapes

The first one is xy is mapped onto -x, y. This one when you keep x the same and take the opposite of y you know that's a reflection over the x axis and last when you switch the x's and y's that will reflect it over line y equals x.

And this bottom part of the quadrilateral gets reflected above it. All Geometry videos Unit Transformations. Place the sharp point of a compass at A and draw two arcs intersecting the line XY. Thank you for watching the video. If the axis of reflection is not on the grid lines, we will need to use a compass to construct the image. 