Given Data

1. A line rises from bottom-left to top-right.
2. The figure is reflected in a vertical mirror.

Question

How does the diagonal appear in the mirror image?

Answer

It falls from top-left to bottom-right.

Solution

1. The mirror reverses the horizontal positions of the endpoints.
2. The endpoint at top-right moves to top-left and the endpoint at bottom-left moves to bottom-right.
3. The reflected diagonal therefore slopes downward from left to right.