GETin: What is..?

There is software named as GEOGEBRA. It is a free, open –source, and multi-platform software that combines dynamic geometry, algebra, calculus, spreadsheet, graphing and statistics in one easy-to-use package. Let us start learning this software. Geogebra was created by Markus Hohenwater in 2001/2002 as a part of his Masters and PhD project in mathematics education at the University of Salzburg in Austria. During that time, geogebra won several international awards, including the European and German educational software awards. Since 2006 geogebra is supported by the Austrian Ministry of Education to maintain the free availability of the software for mathematics education at schools and universities. We will use the latest version of geogebra ( i.e. 4.2)
After you install the geogebra software -

This icon appears on the desktop. Double clicking this icon the following geogebra window appears. There are six main parts of geogebra window. They are as follows: (1) Title bar (2) Menu bar (3) Tool bar (4) Algebra view (5) Graphics view (6) Input bar .

GeoGebra

Now we will move towards the tools that are present in the tool bar. The tool bar is divided in twelve toolboxes. They are as follows: (1)Move (2) New point (3) Line trough two points (4) Perpendicular line (5) Polygon (6) Circle with centre through point (7) Ellipse (8) Angle (9) Reflect object about line (10) Insert text (11) Slider (12) Move graphics view

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

These toolboxes contain various tools which fall in the same category as per the main toolbox. They are as follows:

(1).Move: This toolbox contains three tools in all. They are –

- Move ,

Rotate around point , Record to the spreadsheet.

(2).New point: This toolbox contains six tools in all. They are -

- New point ,

-Point on object ,

-Attach/detach point ,

- Intersect two object ,

- Midpoint or center ,

- Complex number .

(3). Line through two points: This toolbox contains seven tools in all. They are -

- Line through two points ,

- Segment between two points ,

- Segment with fixed length ,

-Ray between two points ,

-Polyline between points ,

-Vector between two points ,

-Vector from point .

(4). Perpendicular line: This toolbox contains eight tools in all. They are –

-Perpendicular line ,

- Parallel line ,

- Perpendicular bisector ,

- Angle bisector ,

- Tangents ,

- Polar or diameter line ,

- Best fit line ,

- Locus .

(5). Polygon: this toolbox contains four tools in all. They are –

- Polygon ,

- Regular polygon ,

- Rigid polygon ,

- Vector polygon .

(6). Circle with centre through point: This toolbox contains nine tools in all. They are -

- Circle with centre through point ,

- Circle with centre and radius ,

- Compass ,

- Circle through three points ,

- Semicircle trough two points ,

- Circular arc with centre between two points ,

- semicircular arc through three points ,

- Circular sector with centre between two points ,

- circumcircular sector through three points .

(7). Ellipse: This toolbox contains four tools in all. They are –

- Ellipse ,

- Parabola ,

- Hyperbola ,

- Conic through five points .

(8). Angle: This toolbox contains six tools in all. They are –

- Angle ,

- Angle with given size ,

- distance or length ,

- Area ,

- Slope ,

- Create list .

(9). Reflect object about line: This toolbox contains six tools in all. They are –

- Reflect object about line ,

- Reflect object about point ,

- Reflect object about circle ,

- Rotate object around point by angle ,

- Translate object by vector ,

- dialect object from point by factor .

(10). Insert text: This toolbox contains seven tools in all. They are –

- Insert text ,

- Insert image ,

- Pen ,

- Freehand shape ,

- Relation between two objects ,

- Probablity calculator ,

- Function inspector .
(11). Slider: This toolbox contains four tools in all. They are –

- Slider ,

- Check box to show/hide objects ,

- Insert button ,

- Insert input box .

(12). Move graphics view: This toolbox contains seven tools in all. They are –

- Move graphics view ,

- Zoom in ,

- Zoom out ,

- Show/hide object ,

- Show/hide label ,

- Copy visual style ,

- Delete object .

NOTE: The uses and how to use these tools you will come to know when you point your cursor on these tool buttons that are shown in the picture.

Let us see one example:-

Question: Construct a regular polygon with six sides using the ‘polygon’ tool.

Solution: (1) select the Circle with Centre through point tool.(1) In the Graphics view, click at a point A and another suitable point B to draw a circle c with centre A through point B.(2) Similarly, draw a circle d through with centre B through point A.(3) Intersect the circles c and d with the Intersect Two Objects tool to get the hexagon’s vertices C and D.(4) Draw circle e with centre C through point A and circle f with centre D through point A.(5) Select the New Point tool and click at the intersection of the circles c and e to get the vertex e to get the vertex E, and at the intersection of the circles c and f to get the vertex F.(6) Draw circle g with centre F through point A.(7) Using the New Point tool, click at the intersection of the circles c and g to get the vertex G.(8) Select the Polygon tool, and click on the vertices, other than A in sequence till you get a closed polygon. The graphics view shows the regular six-sided polygon (i.e., regular hexagon)

To download GeoGebra :
1. Go to GeoGebra.org OR

2. Click on the links below -

	GeoGebra Chrome App
	Windows
	Mac OS X App Store for 10.8 or later Mac OS X App Store for 10.6 and 10.7 Mac OS X Portable
	Ubuntu, Debian (.deb) openSUSE, Fedora (.rpm)
	Java Applet