Reflection of a reflection
a. The Object 1 shown on the left is reflected first in line A and then the image is reflected in line B. What single transformation is equivalent to this?
b. Explore what happens for various starting positions for the object being reflected. What happens, for example, when the object is between the two lines of reflection?
c. Try this with the parallel lines of reflection a different distance apart. Can you articulate a generalisation?
(Idea from Haylock, Mathematics Explained for Primary Teachers, 2018)