How To Construct a Geoboard

How to . . . Construct a Geoboard

You can use a coordinate system to make a Sketchpad geoboard. Straight objects you construct on this geoboard will always stick to the grid dots, just like rubber bands attached to the posts on a physical geoboard. And with a Sketchpad geoboard you can construct polygons, measure slopes of lines, measure perimeters and areas of polygons, and “measure” coordinates of points.

1. Choose Preferences from the Edit menu and click on the Units tab.

2. Set the Distance units to cm and click OK to close the dialog box.

3. Choose Define Coordinate System from the Graph menu.

4. Select the coordinate system by clicking on a grid intersection.

5. Choose Display | Line Width | Dotted to show dots at the intersections.

6. Hide the origin, unit point, and axes.

7. Choose Graph | Snap Points to make points snap to your geoboard’s grid intersections.

Your geoboard is ready for use.