Look in the mirror. Raise
your right hand. Does your reflection also raise its right hand?
Students work individually.
Each student needs:
- 3 sheets of graph paper
- 1 ruler
- color pencils
- stencils (see attached)
- Trace the stencil on one side of the x-axis. Press hard with your
pencil so your figure can be seen through a folded page. Now mark
three points on the figure. Label them A, B, and C.
- Fold the first sheet of paper along the x-axis for a horizontal
line of reflection.
- On the back of the graph paper trace the figure, including A, B,
and C. Press hard with your pencil. Open the paper and trace that
reflection on the front.
- Locate the images of A, B, and C in the reflected figure. Label
the points A', B', and C'.
- Use a straightedge and a red pencil to connect A to A', B to B',
and C to C'.
- Measure the angles where the line of reflection crosses each red
segment. What do you observe?
- Mark the midpoint of each of the red segments. What do you observe?
- Find the coordinates of A, B, and C and A', B', and C'. What do
- Do numbers 1-8 using the y-axis as a vertical line of reflection.
- Do number 1-8 using the graph of y=x as a diagonal line of reflection.
As a result of this activity,
students will learn that some transformations, such as reflections
and rotations, do not change the figure itself, only its position