Each vertex must be moved to the opposite side of the line of reflection while maintaining the same distance from the line.
Practice makes perfect
Before we begin, let's add the given line of reflection to the graph of △ JKL.
To reflect the triangle in y=x, each vertex must be moved to the opposite side of the line of reflection while maintaining the same distance from the line. There are two things we should note.
The vertex at K is on the line of reflection so it will not move at all.
J and L are at a 90^(∘) angle to the line of reflection and equidistant from y=x. When we reflect these vertices, J and L will switch places.
