Geometer's Sketchpad and JavaSketchpad

We cannot use Geometer's Sketchpad activities directly on the internet, because one needs the Geometer's Sketchpad program on your computer to open such *.gsp files. Nevertheless, we can use Geometer's Sketchpad documents on the web in two ways:
- We can insert our sketches as static *.wmf files into a webpage
- We can convert our Geometer's Sketchpad sheet to JavaSketchpad that works on the internet
I show some examples ...

INSERTING YOUR GEOMETER'S SKETCHPAD SKETCHES
We can save our Sketchpad sketches as *.wmf files and insert it as part of our narrative text in our HTML webpages. Here is an example of such a static picture. The quality is excellent!

My GSP sketch!

JAVASKETCHPAD ON THE WEB

Interaction: Dragging points
Many *.gsp files can be converted to a JavaSketchpad applet that can give us interaction and movement on the web. Here is the same gsp-sketch as above, but you can click and drag the red points. Try it!

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(For authors: In Sketchpad 4, save as an HTML document. Be sure to check it, because not all features of Sketchpad convert to Javasketchpad. Specifically, Hide/Show, bisecting angles, dashed lines and arcs are not converted. Then send your GSP file as well as the HTML file for each applet to the editor - I may be able to tweak the code here and there. We then paste the code into the unit HTML webpage. If you are interested to see the HTML and JavaSketchpad code for this webpage, click View Source ...)

Visualisation: Animation
We can also use animation in Geometer's Sketchpad that can be converted to JavaSketchpad for use on the web. Here is the same gsp-sketch as above. Click the Animation button below - it turns ("toggles") the animation on/off. You can also click and drag the points ... What conjectures can be made from the animation?

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Visualisation: Tracing a locus
Another advantage of JavaSketchpad on the web is that we can trace the path of a locus. In the example below we use the same gsp-sketch as above and trace the locus of the midpoint of DE with D stationary and E moving around the circle. Click on the Animate button to toggle the animation on/off. Click on the red X to clear the trace. The locus surely looks like a circle! Can you prove it?

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General instructions on how to interact with JavaSketchpad applets - please read!
  • Wait for the applet to fully load. This may take some time. The applet only becomes active once the status bar says 'Applet started'.
  • Red points can be moved: Place the cursor on the point, left-click, hold and drag ...
  • If there is a button in the applet, click the button to make objects move, or new objects to appear or disappear. (If a button stays down when you click it, click it again to stop the movement, and click again to continue ...)
  • When objects are moving, press '>' on the keyboard to speed up the motion or '<' to slow it down - remember to use SHIFT!
  • Press 'r' on your keyboard to reset the sketch to its initial setting. If the applet is not active, first click anywhere in the applet, then press r.
  • If an object is traced, click the red 'X' button in the lower-right corner to clear traces.
  • The '?' button in the lower-right corner is a link to the JavaSketchpad homepage.

  • Note: Length measurements are given in pixels (short for picture element). A pixel is a single dot on the computer screen.

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Visualisation: A beautiful locus!
While experimenting with the above trace, I accidently "discovered" this beautiful locus! Click on the Animate button ...

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Show and Hide
The Show and Hide features of JavaSketchpad are also useful and can serve different didactical purposes ...
(For authors: Note that the Show/Hide toggle of Geometer cannot convert to Java. The workaround is to make separate Always Show and Always hide buttons - select these in the button properties).
This applet demonstrates Napoleon's Theorem: Three (green) equilateral triangles are drawn on the sides of any triangle ABC and the centres of the three triangles are connected. Drag the red vertices A, B and C ... What conjectures can you make?

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Also see the Shoma Graphing applets page
Also see the Trigonometry notes

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