Tutoriel:Dessin ou Construction
De GeoGebra Manual
Dessiner des figures géométriques
Préparations
- Choisir Dispositions – Géométrie.
Dessiner des images avec GeoGebra
Utilisez la souris et les outils suivants pour dessiner des figures dans la fenêtre Graphique (par ex. carré, rectangle, maison, arbre,…).
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Nouveau point |
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Déplacer |
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Droite passant par deux points |
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Segment entre deux points |
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Effacer l'objet |
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Boutons Annuler/Refaire |
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Déplacer Graphique |
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Agrandissement/Réduction |
Quelle pratique ?
- Comment sélectionner un objet déjà existant.
Idée : Quand le pointeur survole un objet, il le met en surbrillance et change de forme, d'une croix, il devient une flèche. En cliquant vous sélectionner alors l'objet correspondant. - Comment créer un point appartenant à un objet. Hint: Le point est affiché avec une couleur bleu clair. Toujours vérifier que le point appartient bien à l'objet en le déplaçant avec la souris.
- Comment corriger des erreus pas à pas en utilisant les boutons Annuler et Refaire.
Hint: Plusieurs outils autorisent la création de points "à la volée". Aussi il n'est pas nécessaire que des points soient créés avant d'utiliser ces outils.Exemple: L'outil Segment entre deux points peut être appliqués à deux points existant ou dans une fenêtre graphique vierge. En cliquant à deux endroits de la fenêtre graphique, les points correspondants sont créés et le segment les joignant est dessiné.
Sauvegarder des fichiers GeoGebra
Save your drawing
- Open the File Menu and select Save.
- Select the folder GeoGebra_Introduction in the appearing dialog window.
- Type in a name for your GeoGebra file.
- Click Save in order to finish this process.
Hint: A file with the extension .ggb is created. This extension identifies GeoGebra files and indicates that they can only be opened with GeoGebra. Hint: Name your files properly: Avoid using spaces or special symbols in a file name since they can cause unnecessary problems when transferred to other computers. Instead you can use underscores or upper case letters within the file name (e.g. First_Drawing.ggb).
What to practice
- How to open a new GeoGebra window using New Window from the File Menu.
- How to open a blank GeoGebra interface within the same window (menu File – New) Hint: If you didn’t save the existing construction yet GeoGebra will ask you to do so before the blank screen is opened.
- How to open an already existing GeoGebra file (menu File – Open).
- Navigate through the folder structure in the appearing window.
- Select a GeoGeoGebra file (extension ‘.ggb’).
- Click Open.
Rectangle Construction
Preparations
- Summarize the properties of a rectangle before you start the construction.
- Open new GeoGebra file.
- Switch to Perspectives - Basic Geometry.
- Change the labeling setting to New Points Only (menu Options – Labeling).
Introduction of New Tools
- Perpendicular Line and Parallel Line Tools Hint: Click on an already existing line and a point in order to create a perpendicular line/parallel line through this point.
- Intersect Two Objects Tool Hint: Click on the intersection point of two objects to get this one intersection point. Successively click on both objects to get all intersection points.
- Polygon Tool Hint: Click on the Graphics View or already existing points in order to create the vertices of a polygon. Connect the last and first vertex to close the polygon! Always connect vertices counterclockwise!
Hint: Don’t forget to read the toolbar help if you don’t know how to use a tool. Hint: Try out all new tools before you start the construction.
Construction Steps
| 1 | |
Segment AB |
| 2 |  |
Perpendicular line to segment AB through point B |
| 3 | |
New point C on perpendicular line |
| 4 |  |
Parallel line to segment AB through point C |
| 5 | |
Perpendicular line to segment AB through point A |
| 6 |  |
Intersection point D |
| 7 |  |
Polygon ABCD Hint: To close the polygon click on the first vertex again. |
| 8 |  |
Save the construction |
Check your Construction
- Apply the drag test to check if the construction is correct.
- Show the Navigation bar for construction steps (View Menu) to review your construction step-by-step using the buttons.
- Show the Construction Protocol (View Menu) and use it to review your rectangle construction step-by-step.
- Try to change the order of some construction steps by dragging a line with the mouse. Why does this NOT always work?
- Group several constructions steps by setting breakpoints:
- Show the column Breakpoint (Right click on the construction protocol window Columns - Breakpoint)
- Group construction steps by checking the Breakpoint box of the last one of the group
- Change setting to Show Only Breakpoints (Right click on the construction protocol window Options – Show Only Breakpoints)
- Use the navigation bar to review the construction step-by-step. Did you set the breakpoints correctly?
Equilateral Triangle Construction
Preparations
- Summarize the properties of an equilateral triangle before you start the construction.
- Open a new GeoGebra window.
- Hide Algebra View, Input Bar and coordinate axes (View Menu).
- Change the labeling setting to New points only (menu Options – Labeling).
Introduction of New Tools
- Circle with Center through Point Tool Hint: First click creates center, second click determines radius of the circle.
- Show / Hide Object Tool Hint: Highlight all objects that should be hidden, then switch to another tool in order to apply the visibility changes!
- Angle Tool Hint: Click on the points in counterclockwise direction! GeoGebra always creates angles with mathematically positive orientation.
Hint: Don’t forget to read the toolbar help if you don’t know how to use a tool. Hint: Try out all new tools before you start the construction.
Construction Steps
| 1 | |
Segment AB |
| 2 |  |
Circle with center A through B Hint: Drag points A and B to check if circle is connected to them. |
| 3 | |
Circle with center B through A Hint: Drag points to check if circle is connected to them. |
| 4 | |
Intersect both circles to get point C |
| 5 | |
Polygon ABC in counterclockwise direction |
| 6 |  |
Hide circles |
| 7 |  |
Show interior angles of triangle Hint: Click in the middle of the polygon to create all interior angles! |
| 8 | |
Save the construction |
Check your Construction
- Apply the drag test to check if the construction is correct.
- Show the navigation bar or use the Construction Protocol to review your construction step-by-step.
Use the Properties Dialog to Enhance your Construction
There are different ways to access the Properties dialog:
- Right-click (MacOS: Ctrl-click) an object
- Select Object Properties… from the Edit Menu
- Double click an object in move mode
- Toggle Styling Bar on the right hand side of the Graphics View
What to practice…
- Select different objects from the list on the left hand side and explore the available properties tabs for different types of objects
- Select several objects in order to change a certain property for all of them at the same time Hint: Hold the Ctrl-key (MacOS: Open Apple-click) pressed and select all desired objects.
- Select all objects of one type by clicking on the corresponding heading.
- Show the value of different objects and try out different label styles.
