Reflected images are congruent to their pre-image.

True False

Explanation:

Reflected images are a one-to-one copy of their original pre-image counterpart, but everything is flipped. This means the orientation is flipped. Think of an analogue clock that works clockwise when going from 1 to 2 to 3, etc. When you reflect the numbers, going from 1 to 2 to 3 will have you going counterclockwise instead of clockwise. Everything else is kept intact though.

Here's another way to look at it. Imagine you had a marker that could write on a vertical sheet of glass. Now draw a triangle on it, or any shape you want. Have a friend stand on the other side of the glass. Your friend will see the exact same triangle that you do, but they'll see the reflected version of it. You could draw the analogue clock mentioned earlier to see how the orientation flips when the reflection occurs.

Because a reflection keeps the same image, this means that we have an isometry. The lengths, distances, area, shape, etc of the figure is preserved.