Dr. Geo User's Manual -- Macro-Construction

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## Macro-Construction

Macro-constructions are a bit like a procedure which receives as input figure items and then returns one or more figure items, constructed by the macro-construction. They are built on a model defined by the user. This means that the user has to build a construction sequence only once. Then she can tell DR. GEOthat she wants this sequence to be recorded in a macro-construction. To record a construction sequence, DR. GEOneeds to know which are the initial items of the sequence and the resulting items. Of course the resulting items must depend only on the initial items; otherwise Dr. Genius would not be able to deduce the resulting items from the initial ones.

Using its knowledge of the initial and resulting items, DR. GEOdeduces the construction sequence and saves it in a macro-construction. The user can then execute this macro-construction simply by inputting (initial) items (they must match the type) in the figure. The macro-construction can then build the resulting items.

(!) Invisible intermediate figure items are also built by the macro-construction. These items are necessary to build the resulting items.

To illustrate the macro-construction feature, we will use an example in which the user wants to record the construction of a circle with a given center which passes through three points, also given.

Our initial figure

Before constructing the macro-construction, the user needs to construct the final figure; it is used as a pattern from which to build the macro-construction.

Our figure with the resulting construction

- Constructing a Macro-Construction
- Executing a Macro-Construction

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