Reflection Mirror

Note: Reflection is like a mirror as

the post-image is backwards

In this image, △A is reflected by 4 units over the x-axis

Notice how the image looks upside down in terms of the pre-image.

A reflection, is a rigid motion transformation that flips a figure over a line called the line of reflection.

reflection x-axis
Reflection y-axis

In this case, the pre-image and image look the same because we have an isoceles triangle. We can say that there is a translation of 4 units to the right or that the shape was reflect over the y-axis/

Reflection line of symmetry

Since there is no vertical line of symmetry, the shape looks different after the transformation . However, there is a horizontal line of symmetry, so reflecting this figure over the x-axis would maintain the shape.