Exploring with Reflection over the Y-Axis
The following applet allows you to explore with a triangle reflection over the y-axis. Your goal is to take the blue triangle and drag A'', B'', and C'' so that it matches the reflection of the pre-image of triangle with vertices A, B, and C. When you think you have the correct reflection of the image, check "Check Answer" and you will be able to see if you have correctly moved the vertices. To get a new triangle to try, refresh your window.