Geogebra/C2/Understanding-Quadrilaterals-Properties/English
Title of script: Understanding Quadrilateral properties
Author: Madhuri Ganapathi
Keywords: Polygon, Angle, Parallel line, Segment between two points, Insert text, “Distance or Length” tool, New Point, Algebra View, Quadrilaterals, video tutorial
| Visual Cue | Narration |
|---|---|
| Slide Number 1 |
Hello everybody. Welcome to this spoken tutorial on Understanding Quadrilaterals Properties in Geogebra. |
| Slide Number 2
Note |
The intention of this tutorial is not to replace the actual compass box
Construction in GeoGebra is done with the view to understand the properties. |
| Slide number 3
Pre-requisites |
We assume that you have the basic working knowledge of Geogebra. If not, please visit the spoken tutorial website for relevant tutorials on Geogebra. |
|
Slide number 4 Learning Objectives |
In this tutorial, we will learn to construct quadrilaterals
|
| Slide Number 5
System Requirement |
To record this tutorial I am using Linux operating system Ubuntu Version 11.10 LTS Geogebra Version 3.2.47.0 |
| Slide Number 6
GeoGebra Tools used in this tutorial |
We will use the following tools of Geogebra for construction
|
| Switch to geogebra window
Dash home >>Media Apps>> Under Type>>Education>>Geogebra |
Let's open a new Geogebra window.
To do this click on Dash home and Media Apps. Under Type click on Education and then Geogebra. |
| Click on “Circle with Centre through Point” tool >>
Construct a circle |
Let's construct a circle with center 'A' which passes through point 'B'.
To do this, click on the “Circle with Center through Point” tool from toolbar. |
| Click on the drawing pad. | Click on the drawing pad.
Point 'A' is the center. |
| Click a little away from point A. | Then click again and we get point 'B'.
The circle is complete. |
| Construct circle with center C which passes through D>>
click point C on >>then point D |
Let's construct another circle with center 'C' which passes through 'D'.
Click on the drawing pad. It shows point 'C' as the centre. |
| Click a little away from point C such that
the new circle intersects with the previous circle. |
Then click again and we get point 'D'. |
| Point to the intersection points. | The circles intersect at two points. |
| Click “New Tool” >> select “Intersect Two Objects” | Click the “Intersect Two Objects” tool under “New Point”. |
| Mark the points of intersection. | Mark the points of intersection as 'E' and 'F'. |
| Click on polygon tool | Next, click on the “Polygon” tool. |
| Click on the points A E C F and A again. |
Click on the points 'A', 'E', 'C', 'F' and 'A' again. A simple quadrilateral is drawn. |
| Point to the “Algebra View” panel. | We can see from “Algebra View” that 2 pairs of adjacent sides are equal.
Do you know why? Can you figure out the name of the quadrilateral? |
| Click on "Save As" >> type "simple_quadrilateral" in file
name >> click on save |
Let us save this file now. Click on “File”>> "Save As". I will type the file name as "simple-quadrilateral" and click on “Save”. |
|
Click on File>>New |
Next, let us construct a Quadrilateral with diagonals. Let's open a new Geogebra window, by clicking on “File” and ”New ” |
| Click segment between two points tool>>draw AB | Let's draw a segment first.
Select “Segment between Two Points” tool from the toolbar. On the drawing pad, mark points 'A' and 'B'. Segment 'AB' is drawn. |
| Construct a circle with center 'A' >> through point 'B'. |
Let's construct a circle with center 'A' which passes through point 'B'. |
| Click on the “Circle with Centre through Point” tool |
To do this click on the “Circle with Centre through Point” tool. |
| Click on point 'A' and then on 'B'. | Click on point 'A' then click on 'B'. |
| Click on “New Point” tool >> Mark point 'C' on the circumference | Using the “New Point” tool,
let's mark a point 'C' on the circumference of the circle. |
| Click segment between two points>> connect 'AC' | Next, using the “Segment between Two Points” tool,
join the points 'A' and 'C'. |
| Let's construct a parallel line to segment 'AB' which passes through 'C'. | |
| Click “Parallel Line” tool | Select the "Parallel Line" tool from the toolbar. |
| Click on point C and segment AB. | First click on point 'C'
and then click on segment 'AB'. |
| Click “Parallel Line” tool>>click on point B and segment AC. | Let us repeat the process for point 'B'.
Click on point 'B' and then click on segment 'AC'. |
| Point to the intersection point >> mark point D | Notice that the parallel line to segment 'AB'
and the parallel line to segment AC intersect at a point. Let's mark the point of intersection as 'D'. |
| Click “segment between two points” tool >> Connect the points | Using the “Segment between Two Points”,
let's connect the points 'A'&'D', 'B'&'C' A Quadrilateral ABCD with diagonals AD and BC is drawn. |
| diagonals intersect at point >>mark the point of intersection | Diagonals intersect at a point.
Let us mark the point as 'E'. |
| Using “Distance or Length” tool,
let's check whether the diagonals bisect each other. | |
| Click on “Angle” tool >> “Distance or Length” tool. | Under “Angle”, click on the “Distance or Length” tool. |
| Click on the points A, E and E, D
Click on the points C, E and E, B |
Now, click on the points A, E and E, D
And then click on the points C, E and E, B |
| Next, we will check whether the diagonals are perpendicular bisectors. | |
| Click “Angle” tool>>measure the angles AEC and CED |
To measure the angle, click on the “Angle” tool. Now, click on the points AEC and then CED |
| Select the “Move” tool from the toolbar | Let's select the “Move” tool from the toolbar. |
| Use the “Move” tool to move point 'A'. | Use the “Move” tool to move point 'A'. |
| Properties | Notice that the diagonals always bisect each other
and are also perpendicular bisectors. |
| Click on "Save As" >> type "quadrilateral" in filename
>> click on save |
Lets save this file now.
Click on “File”>> "Save As". I will type the filename as "quadrilateral" click on “Save”. |
| Slide Number 6
Summary |
Lets summarize. In this tutorial we learnt to construct quadrilaterals using the following tools - Circle with centre through point, Polygon, Angle, Parallel line, Segment between two points, Insert text We also learnt the properties of * Simple quadrilateral * Quadrilateral with diagonals |
| Slide number 7
Assignment |
To practice- Draw a line segment AB Mark a point C above the line Draw a parallel line to AB at C Mark two points D and E on the Parallel Line Join points AD and EB , making a trapezium ADEB Draw perpendicular lines to segment AB from D and E Mark the points of intersection F and G of the perpendicular lines and AB Measure distance DE and height DF |
| Show the output of the Assignment | The output should look like this. |
| Slide number 8
Acknowledgement |
Watch the video available at http://spoken-tutorial.org/What is a Spoken Tutorial It summarises the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it |
| The Spoken Tutorial Project Team :
Conducts workshops using spoken tutorials Gives certificates to those who pass an online test For more details, please write to contact@spoken-tutorial.org | |
| Spoken Tutorial Project is a part of the Talk to a Teacher project
It is supported by the National Mission on Education through ICT, MHRD, Government of India More information on this Mission is available at http://spoken-tutorial.org/NMEICT-Intro ] This is Madhuri Ganapathi from IIT Bombay signing off. Thanks for joining |
