Reflections over Intersecting Lines
- Bob Allen
2. Record the original measure of BED and JEJ" as Trial 1. Then move any or all of the following objects: points D or B, or the flag. Record the new angle measures, BED and JEJ'', label them Trial 2 in the box below.Repeat the previous step three more times, labelling new steps as Trials 3 through 5 respectively. Your data should look something like this: Trial 1 ### ### Trial 2 ### ### and so on.
Compare the two angle measures in your table. What do you notice? Write a conjecture about the those two values. Here's a start: If a figure is reflected over two intersecting lines, then...
What does this look like?
Look at the preimage flag and the second image (double prime). Does this look like a translation, rotation, reflection, or something new? What else do you notice? How does it move? Are any other points important? (Yes, this is a little open ended.)