Geogebra Clix C01

File:C01 - Geogebra, April 2018.odt

Getting familiar with the Geogebra interface

The above image shows you the Geogebra window. After opening Geogebra, you will see the application window as above. The user can define the graphics view in terms of the axes, the grid, scale of the axes, etc. The Move button - which allows objects to be moved is highlighted in blue.

Tool bar introduction

In this section you will be introduced to the basic constructions available on the tool bar.

• Introduction to the tool bar
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  Moving objects

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  Moving by rotating around a point

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  Drawing segments and lines

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  Drawing parallel lines

The Geogebra tool bar is very versatile - the construction follows the processes that we would normally follow in paper and pen construction. Some six important categories in the tool bar are discussed below:

1. Moving objects:Geogebra allows you to move object constructed freely by dragging the object. You can also select an object and move it by rotating aroung a point.
2. Plotting points: There are different ways of plotting points on the Geogebra graphics pad. You can plot a point anywhere on the graphics view - this is a free point. You can also plot on an object or as an intersection of two objects; in both the cases the point is a dependent object.
3. Drawing lines: The menu for lines and segments also allows multiple constructions - segments,lines, rays and vectors
4. Drawing multiple lines: Multiple lines can also be drawn in Geogebra. Parallel lines, perpendicular lines, angle bisectors and perpendicular bisectors can be drawn.

Saving and exporting

1. You can save Geogebra file from the File menu.
2. You can also export the Geogebra file as an image (.png format) or as an animated graphic (.gif format).
3. If you export the Geogebra file as html you can publish it on the repository for Geogebra files.

Measuring an angle

• Measuring an angle
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The above set of images show how to measure angles in Geogebra.

Typing text in a textbox

• Using the text box
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The textbox is used to write descriptive text in a Geogebra file. The first image shows you the option in the tool bar which will be used to insert a text box. After selecting the text box option, you can click anywhere on the graphics pad to insert the text box. The next two images show how symbols and prior defined objects can be inserted. For example, in the third image, the "α" object is a prior defined object - the angle measure. This feature allows the text box to dynamically capture the changes in the Geogebra file.

Defining a slider

One of the powerful features of Geogebra is the dynamic feature. You can vary parameters of the shape that you want to animate and see how properties change.

• Using the slider
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  Defining the slider

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  Polygon with a slider for number of sides

1. The first image shows you how to define a slider. In the slider dialog box, you can define the name, the range of values for the parameter and the increment to be used. You can either define a slider of sides or angles.
2. The second image shows the construction of a polygon with a slider defined for the number of vertices.
3. In the file you have worked with, a slider has been created for angles.
4. When you define a slider, you can also set up animation on - this keeps changing the value of the parameter and keeps changing the sketch

Defining a checkbox

A checkbox is a useful way to control the sequence of display of objects in a Geogebra file and hence can be an useful way to structure a lesson.

• Using the check box
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The first image above shows where the check box option is located on the menu. Once the check box is selected, click anywhere on the graphics view to create a check box. The display of any created object can be allowed or not allowed by linking it to the checkbox; this is a 1:1 linkage. For each object, a new check box must be created.

• Check box created
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In the first image above, the view shows how a check box looks when created. This check box is linked to the text box describing an angle type; when it is checked the text box displays. Otherwise the text box is not displayed.