Dynamic texts in GeoGebra allow flexible creation of numerical and symbolic expressions connected to multiple dynamic objects on the screen. The following video demonstrates the principles of creating different types of expressions depending on defined variables. Values within the expressions will be updated with the variables.
In the text editing box, choose from the "Objects" list variables already defined. Current values of these variables will be displayed in the expression.
LaTex formula can also be activated to create math expressions such as fractions, exponents or roots.
In the following applet, right click each expression to examine the "Object properties". Click the 'Text' tab to see and modify the input. Drag the sliders to see how the values of a and b change and update the expressions.
This second video is a simple setup for an investigation of angle relation in a quadrilateral. Dynamic texts including angles and calculation are shown. The figure is then modified by attaching points to a circle centred at C. The expression is changed accordingly and a new question is formed.