Finding reflections using tracing paper

Sometimes the mirror line, or line of reflection, is at an angle.

Example

Reflect the given shape in the diagonal line.

Shape and line of reflection

Use tracing paper to copy the shape and line of reflection.

Tracing of shape turned over and matched up with line of reflection

Turn the tracing paper over and match up line of reflection and the vertices.

Reflection of the original shape drawn in green

Place dots to mark the position of the vertices, then remove the tracing paper and draw the reflection of the shape.