Geogebra Animated GIFs (Hello, World)

So, I created the above animated GIF using Geogebra. I realize that it just a perpendicular bisector, but it is a start of what one can do with the Geogebra animated GIF feature.

I can think of a few reasons we'd want to do something like this. First, we can see a construction or drawing being created. It helps to see how the lines are drawn rather than just the final product. We don't draw the perpendicular bisector and then make the circles match. Second, we can begin having a discussion about how do we prove this. What's given? What do we get? How do we get from there to here? While the perpendicular bisector is a "classic" textbook proof, it can begin the discussion for richer problems. See the many GIFs created by Tim Brzezinski and shared on his Twitter account. They are challenging and attainable by high school students. Third, oh boy if we could get students making these. Look at all the algebra, geometry, and logic they'd need.

Here are the steps I took. To save you some time, you will want the desktop version of the software. For some reason, the web version doesn't allow Exporting as a GIF.
1) Create a slider
I started from 0 to 2 with steps of 0.1. I added on up to 4 as I realized that I would have 4 things that would be happening during my animation.
2) Think about the order you want things to happen
I can't stress this enough. For this simple one, I didn't write anything down. Segment, left circle, right circle, bisector, angle and equal segments. I should have written things down. I really should have. Feel free to open (and edit) the file below to see the Construction Protocol as well as how things are defined. Now that I've done it, I would really take the time to write this down in advance.
3) Make your construction
As part of this, you'll want each of the pieces to be defined by your slider (for example I wanted to second circle to start at a=1 so its radius was 4a-4 (I also only show it from a=1 to a=2). I also use a simple "Condition to Show Object" under the Advanced Object Properties based on the slider timeline. I needed to change a few colors of objects as well as hide labels (I did this ONLY when I was done with that part of the animation).
4) Change the size of the graphics view
I love Geogebra, but one of it's quirks is that if you save something that is full screen. That is how the next person will open it. If you save it in a 100x300 pixel window, that is how your file will open. Resize your window so that you will have an appropriately sized GIF. Also, if you select the properties of the slider, you can move it off the screen before you export. The slider will still define what gets animated.
5) Download file to the Desktop
Seriously, I did all my work online and then needed to download the file so that I could then export an animated GIF to later upload to various sites.
6) Export as animated GIF
Find this under File, Export. You will be asked how long you want between stills (the step interval). I wanted a 4 second GIF (4000 ms) and I had 40 steps. [I will leave this as a problem for the reader to solve.]

I hope these steps help. I am by no means an expert at this, but I am wish to improve and help others. Post a comment below with your tips or questions.




Get the file here