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GeoGebraClasse GeoGebra

Introduction to dynamic texts

Introduction

A dynamic text is a text where the contents is dynamic, i.e. changes as the underlying construction changes. You can insert the value of any object, or even make calculations directly in the text itself. When these values change, the text changes to reflect this. (This side originally created by Jonas Hall)

Sample construction

When to use

Use this whenever a picture isn't worth a thousand words ;-)
  • To make visible the details of a calculation
  • To spell things out clearly
  • To show the numerical side of things

How do you do this?

The construction above uses the following KEY ELEMENTS:
  • A triangle from three points: Click the polygon tool, then click three times. Finish by clicking the first point again.
  • A calculated number: Here Sum = α + β + γ. You get greek letters by pressing Alt-a, Alt-b and Alt-g.
  • A text label: This is created by just dragging the variable "Sum" from the Algebra window to the Graphics window.
  • A dynamic text: Created with the dynamic text tool by alternatively typing and selecting mathematical objects from the drop down menu.

Screencast of construction

More examples

Here is another example of using dynamic texts, here in the complicated world of adding fractions.