GeoGebra Essentials 9 – Texts and Variables

This is the eighth tutorial in the GeoGebra Essentials Series. If you are not familiar with GeoGebra, you may want to read the Introduction to GeoGebra post and the earlier tutorials in this series.

In the tutorial below, menu commands, located in the menu bar, are in brown bold text, and submenus are denoted by the > symbol. For example, Options>Labeling> New Points Only means, click the Options menu, choose Labeling from the list, then select New Points Only. The name of the tools are colored orange. For example, New Point means the new point tool.

In this tutorial, we  learn how to use the Text tool of GeoGebra. We will use a previous tutorial on how to use sliders, and then, learn how to the text tool and how concatenate text and variables. The output of this tutorial can be viewed here.

In doing the tutorial, we are going to learn the following:

  • Understand the difference between text and variables in GeoGebra
  • Concatenate text and variables 
1.) Open GeoGebra. Click Algebra & Graphics in the Perspective panel.
2.) Follow steps 1-8 of GeoGebra Tutorial 4.
3.) To place the first line, select the Text tool and click on the vacant part of the Graphics view to display the text tool dialog box.

4.) Type the following: The equation of the line is and then click the Objects drop down and select a. Notice that a, the name of the line is displayed in the Edit box, and it’s equation is displayed in the Preview box.

 5.) To display the second line, type The slope of the line is and then select  from the Objects drop down, and then type and its y-intercept is and then click b in the Objects drop down.

Notes:

  1. The blue-colored text the strings of texts whose values never change.  These should be enclosed with double quotations.
  2. The variables a, b, and m, are names/values of mathematical objects in GeoGebra.  It can be a number, an equation, coordinates, etc.

Updated: 23 December 2015 (GeoGebra 5.0)

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