Redefining objects is a very versatile tool to change a construction. Please Note that this may also change the order of the construction steps in the Construction Protocol.
In GeoGebra, an object may be redefined in different ways:
·
Select the Move tool and double click on any object in the Algebra View.
o For free objects an editing field is opened allowing you to directly change the algebraic representation of the object. Hit the Enter-key in order to apply these changes.
o For dependent objects the Redefine dialog is opened allowing you to redefine the object.
·
Select the Move tool and double click on any object in the Graphics View. This opens the Redefine dialog and allows you to
redefine the object.
· Overwrite any object by entering its name and the new definition into the Input Bar.
· Open the Properties Dialog and change the definition of an object on tab ‘Basic’.
Note: Fixed objects cannot be redefined. In order to
redefine a fixed object, you need to free it first using the Properties Dialog.
Examples:
· In order to place a free point A on an existing line h, you need to open the Redefine dialog window for point A and enter Point[h] in the appearing text field before clicking ‘OK’. To remove the point from this line and make it free again, you need to redefine it to some free coordinates like (1, 2).
·
Another example is the conversion of a line h through two points A
and B into a segment. Open the Redefine dialog for line h and enter Segment[A, B] in
the appearing text field. This also
works the other way round.