Education Technology

Solution 10033: Creating Parabolas in Cabri Geometry™ II.

How do I create a parabola in Cabri Geometry II?                    

Below are two methods of creating a parabola in Cabri Geometry II.

1) From a new Cabri Geometry II file, select the Show Axes and Define Grid options from the Draw menu, then select the Conic tool. Choose five points to complete the Conic. If using the pointer to select points (-2,4), (-1,1),(0,0),(1,1) and (2,4), a parabola will be created. The Define Grid option snaps the cursor to the exact points on the grid.

2) Parabolas can also be created without using the conic tool exclusively. Do this by selecting File Open, select the Macros directory (folder), and select the 'Parabola(Focus & Directrix)' macro. This parabola macro will appear in the Macro toolbox. Then draw a line and a point, select the parabola macro, select the line and the point and a parabola will be displayed.

The macro was constructed as follows:

• File, Open.
• Select the Macros directory.
• Then the Macro Files directory.
• Then the file called 'Parabola(Focus & Dir)(Fig)'.
• This is the construction for the parabola macro.

Please see the Cabri Geometry II guidebook for additional information.