Creating Custom Tools

One of the nice features of GeoGebra is that you can make custom tools for use in an applet. We will examine creating tools for giving the inscribed and circumscribing circle of a triangle. Start by producing a sample triangle.

Add in the extra objects we want created by the tool and set the styles of those objects.

From the Tools menu, select the item for Create New Tools

This will bring up a dialog box. The first panel and a drop down menu for selecting the output objects of the tool.

The second tab lets you select the inputs for the tool. Normally GeoGebra will select them for you. In this case you might want to uses sides rather than vertices.

The third tab lets you select a name for the tool. This automatically generates a command name so that you can use the tool with the input line.

Hit finish and see the tool in the toolbar.

It is useful to test the tool. We create three points.

Using the three points we try out the tool and see it works.

We use a screen capture tool to create a better icon for the tool.

Then we go back to the Manage Tools item in the Tools menu get a dialog for adding the icon

Select the icon button to get a dialog for selecting the icon.

We can see the icon in the tool bar.

We can also save tools for use in other pages. (Assume we have created a second tool for finding the inscribed circle.) Select the Manage Tools item and select both tools.

Select the Save As button.

Note that we are saving as a ggt file rather than a ggb file.

© Mike May, S.J., 2009