We've explored reflections, rotations, and translations. Now we're going to go a bit more basic and work only with reflections.[br][br]You will be exploring what happens to a figure when reflected over two parallel lines.[br][br][color=#ff00ff][b]REMEMBER[/b][/color]: Mistakes are a good thing. No one, and I mean no one, gets every construction right on the first try. This isn't brain surgery. Nothing will crash if you make a mistake. And starting over is sometimes the best way to go. So there's the do over symbol in the upper right hand corner.
1. Measure [math]\angle[/math]BED in that order. If you get an angle measure larger than 180[math]^\circ[/math], undo and try again.[br]2. Using the [b]Reflect about Line[/b] tool, reflect the flag over line[i] f[/i].[br]3. Using the [b]Reflect about Line[/b] tool, reflect the flag prime over line g.[br]4. Measure [math]\angle[/math]JEJ''.
2. Record the original measure of [math]\angle[/math]BED and [math]\angle[/math]JEJ" as Trial 1. [br][br]Then move any or all of the following objects: points [i]D or B[/i], or the flag. [br]Record the new angle measures, [math]\angle[/math]BED and [math]\angle[/math]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.[br][br]Your data should look something like this:[br] Trial 1 ### ###[br] Trial 2 ### ###[br][br]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:[br][br]If a figure is reflected over two intersecting lines, then...
Look at the preimage flag and the second image (double prime). Does this look like a translation, rotation, reflection, or something new?[br][br]What else do you notice? How does it move? Are any other points important? (Yes, this is a little open ended.)
Press the Turn In button ONCE and then wait patiently for a few moments. If nothing seems to happen, or if you do not have a Turn In button, call for me.[br][br]If you have homework to complete, do that while everyone finishes.