Using a Custom Tool

Custom tools are easy to use, even before you learn to make one yourself. In this example, you’ll use custom tools that are already defined in one of the sample documents that comes installed with Sketchpad. The document Sample Tools.gsp contains several custom tools. Just by opening that document, you can use its tools in your own sketch.

1. Open the document Sketchpad | Samples | Custom Tools | Sample Tools.gsp.

2. Press and hold on the Custom tools icon in the Toolbox. The Custom Tools menu appears.

3. Choose Circumcircle from the menu. This custom tool constructs a triangle and its circumcircle given three points.

4. Move your mouse over the sketch and click in three different places. A triangle appears with its circumcircle—the circle that passes through all three vertices.

5. Continue using the Circumcircle tool. Click three more times in the sketch for each triangle you want to construct. You can click in empty space, on existing points, on paths, or on intersections just as you can with the Point, Compass, and Straightedge tools.

You can also press, drag, and release to get the same effect as two clicks (one where you pressed, and one where you released).

6. When you’re finished making triangles with circumcircles, click on any other tool in the Toolbox or press the Esc key.

To resume making circumcircles, click the Custom tool icon again. You don’t need to press and hold to choose from the Custom Tools menu the next time—just click the Custom tool icon to activate it. Press and hold the Custom tool icon in the Toolbox only when you want to switch to a different custom tool from the menu.

Subtopics:
Givens and Results of a Tool
Matching Given Objects