Difference between revisions of "Geogebra/C3/Relationship-between-Geometric-Figures/English-timed"

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||01:27
 
||01:27
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|| To do this let us select the "Regular Polygon" tool from the tool bar click on the "Regular Polygon" tool click on any two points on the drawing pad.
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|| To do this let us select the '''Regular Polygon''' tool from the tool bar click on the '''Regular Polygon''' tool click on any two points on the drawing pad.
  
 
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|-
 
||01:38
 
||01:38
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||We see that a dialog box open with a default value '4'.
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||We see that a dialog box open with a default value '''4'''.
  
 
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||01:43
 
||01:43
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||A square  'ABCD' is drawn.  
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||A square  '''ABCD''' is drawn.  
  
  
 
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|-
 
||01:46
 
||01:46
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||Let's tilt the square Using the “Move” tool which is at the left corner.
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||Let's tilt the square Using the '''Move''' tool which is at the left corner.
  
 
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|-
 
||01:51
 
||01:51
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||Select the "Move" tool from the tool bar, click on the Move tool
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||Select the '''Move''' tool from the tool bar, click on the Move tool
  
 
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|-
 
||01:56
 
||01:56
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||Place, the mouse pointer on  'A' or on 'B'. I will choose B  
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||Place, the mouse pointer on  '''A''' or on '''B'''. I will choose B  
  
 
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|-
 
|-
 
||02:10
 
||02:10
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||Let's construct a perpendicular bisector to the segment 'AB'.  
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||Let's construct a perpendicular bisector to the segment '''AB'''.  
  
 
|-
 
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||02:15
 
||02:15
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||To do this Let's Select  “Perpendicular bisector” tool from the tool bar.
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||To do this Let's Select  '''Perpendicular bisector''' tool from the tool bar.
  
 
|-
 
|-
 
||02:20
 
||02:20
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||Click on the "Perpendicular bisector" tool.  
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||Click on the '''Perpendicular bisector''' tool.  
  
 
|-
 
|-
 
||02:22
 
||02:22
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||click on the point 'A'  
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||click on the point '''A'''  
  
 
|-
 
|-
 
||02:24
 
||02:24
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||and then on  point'B'  
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||and then on  point'''B'''  
  
 
|-
 
|-
 
||02:26
 
||02:26
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||We see that a "Perpendicular bisector" is drawn.
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||We see that a '''Perpendicular bisector''' is drawn.
  
 
|-
 
|-
 
||02:30
 
||02:30
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||Let's construct a second perpendicular bisector to segment 'BC' to do this   
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||Let's construct a second perpendicular bisector to segment '''BC''' to do this   
  
 
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||02:36
 
||02:36
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||Select  “perpendicular bisector” tool from the tool bar, click on the  “perpendicular bisector”  tool.
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||Select  '''perpendicular bisector''' tool from the tool bar, click on the  “perpendicular bisector”  tool.
  
 
|-
 
|-
 
||02:42
 
||02:42
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||click on the point 'B'  
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||click on the point '''B'''  
  
 
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||02:44
 
||02:44
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||and then  on point 'C'  
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||and then  on point '''C'''  
  
 
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||02:50
 
||02:50
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||Let us mark this point as 'E'
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||Let us mark this point as '''E'''
  
 
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|-
 
||02:54
 
||02:54
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||Let's now construct a circle with centre as 'E' and which passes through C .
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||Let's now construct a circle with centre as '''E''' and which passes through C .
  
 
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||03:01
 
||03:01
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||Let's select the "circle with centre through point" tool from tool bar click on the "circle with centre through point" tool.
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||Let's select the '''circle with centre through point''' tool from tool bar click on the '''circle with centre through point''' tool.
  
 
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||03:09
 
||03:09
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||Click on point 'E' as centre and which passes through 'C'. Click on the point 'E' and then on point 'C'.
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||Click on point '''E''' as centre and which passes through '''C'''. Click on the point '''E''' and then on point '''C'''.
  
 
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||03:42
 
||03:42
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||To do this Let's select the "Move" tool from the tool bar, click on the "Move" tool place the mouse pointer on 'A' or 'B'. I will choose 'A'.
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||To do this Let's select the '''Move''' tool from the tool bar, click on the '''Move''' tool place the mouse pointer on '''A''' or '''B'''. I will choose '''A'''
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+
 
|-
 
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||03:52
 
||03:52
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||Place the mouse pointer on 'A' and drag it with the mouse to animate.
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||Place the mouse pointer on '''A''' and drag it with the mouse to animate.
  
 
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||04:04
 
||04:04
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||Click on "File" "Save As".   
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||Click on '''File''' '''Save As'''.   
  
 
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||04:07
 
||04:07
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||I will type the file name as "cyclic_quadrilateral"
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||I will type the file name as '''cyclic_quadrilateral'''
  
 
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||04:35
 
||04:35
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||Let's now construct a triangle to do this , Let's select the "Polygon" tool from the tool bar, Click on the "Polygon" tool.
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||Let's now construct a triangle to do this , Let's select the '''Polygon''' tool from the tool bar, Click on the '''Polygon''' tool.
 
   
 
   
 
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||04:55
 
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||To do this Let's select the "Angle" tool from the tool bar, click on the Angle tool.
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||To do this Let's select the '''Angle''' tool from the tool bar, click on the Angle tool.
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+
  
 
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||05:00
 
||05:00
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||Click on the points 'B,A,C' , 'C,B,A' and 'A,C,B'.
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||Click on the points '''B,A,C''' , '''C,B,A''' and '''A,C,B'''.
  
 
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||05:21
 
||05:21
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||Select the "Angle bisector" tool from the tool bar,  
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||Select the '''Angle bisector''' tool from the tool bar,  
  
 
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||05:25
 
||05:25
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||click on the "Angle bisector" tool.Click on the points 'B,A,C' .
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||click on the '''Angle bisector''' tool.Click on the points '''B,A,C''' .
  
 
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||05:32
 
||05:32
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||Let's select the "Angle bisector" tool again from the tool bar to construct second angle bisector.
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||Let's select the '''Angle bisector''' tool again from the tool bar to construct second angle bisector.
  
 
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||05:39
 
||05:39
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||click on the "Angle bisector" tool and the tool bar, click on the points A,B,C.
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||click on the '''Angle bisector''' tool and the tool bar, click on the points A,B,C.
  
 
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||05:52
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||Let's mark this point as 'D'.
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||Let's mark this point as '''D'''.
  
 
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||06:02
 
||06:02
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||Select “perpendicular line” tool from tool bar,click on the “perpendicular line” tool, click on the point D and then on segment AB.
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||Select '''perpendicular line''' tool from tool bar,click on the '''perpendicular line''' tool, click on the point D and then on segment AB.
  
 
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||06:17
 
||06:17
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||Let's mark this point as 'E'.
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||Let's mark this point as '''E'''.
  
 
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||06:20
 
||06:20
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||Let's now construct a circle with centre as D and which passes through 'E'.
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||Let's now construct a circle with centre as D and which passes through '''E'''.
  
 
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||06:27
 
||06:27
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||Let's select the "compass" tool from tool bar , click on the "compass" tool,click on the point D as centre and DE as radius.
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||Let's select the '''compass''' tool from tool bar , click on the '''compass''' tool,click on the point D as centre and DE as radius.
  
 
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||06:37
 
||06:37
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||Click on the point 'D' and then on point 'E' and 'D' once again to complete the figure.
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||Click on the point '''D''' and then on point '''E''' and '''D''' once again to complete the figure.
  
 
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Revision as of 11:28, 5 September 2014

Title of script: Relationship between different Geometric Figures

Author: Madhuri Ganapathi

Keywords: video tutorial

Click here for Slides

Time Narration
00:00 Hello.
00:01 And welcome to the spoken tutorial on Relationship between different Geometric Figures in Geogebra
00:07 We assume that you have the basic working knowledge of Geogebra.
00:11 If not, please go through the “Introduction to Geogebra” tutorial before proceeding further.
00:18 Please note that the intention to teach this tutorial is not to replace the actual compass box.
00:24 Construction in GeoGebra is done with the view to understand the properties.
00:29 In this tutorial we will learn to construct


00:32 Cyclic quadrilateral and In-circle
00:35 To record this tutorial I am using

Linux operating system

00:39 Ubuntu Version 10.04 LTS
00:43 And Geogebra Version 3.2.40.0
00:48 We will use the following Geogebra tools for the construction
  • compass
  • segment between two points
  • circle with center through point
  • polygon
  • perpendicular bisector
  • angle bisector and
  • angle
01:02 Let us switch on to the Geogebra window.
01:05 To do this let us click on applications, Education and Geogebra.


01:13 Let me resize this window.
01:18 Click on the options menu click on font size and then on 18 point to make the figure clear.


01:25 Let us construct a cyclic quadrilateral.
01:27 To do this let us select the Regular Polygon tool from the tool bar click on the Regular Polygon tool click on any two points on the drawing pad.
01:38 We see that a dialog box open with a default value 4.
01:42 click OK.


01:43 A square ABCD is drawn.


01:46 Let's tilt the square Using the Move tool which is at the left corner.
01:51 Select the Move tool from the tool bar, click on the Move tool
01:56 Place, the mouse pointer on A or on B. I will choose B
02:01 Place the mouse pointer on B and drag it with the mouse. We see that the square is in the tilted position now.
02:10 Let's construct a perpendicular bisector to the segment AB.
02:15 To do this Let's Select Perpendicular bisector tool from the tool bar.
02:20 Click on the Perpendicular bisector tool.
02:22 click on the point A
02:24 and then on pointB
02:26 We see that a Perpendicular bisector is drawn.
02:30 Let's construct a second perpendicular bisector to segment BC to do this
02:36 Select perpendicular bisector tool from the tool bar, click on the “perpendicular bisector” tool.
02:42 click on the point B
02:44 and then on point C
02:46 We see that the perpendicular bisectors intersect at a point .
02:50 Let us mark this point as E
02:54 Let's now construct a circle with centre as E and which passes through C .
03:01 Let's select the circle with centre through point tool from tool bar click on the circle with centre through point tool.
03:09 Click on point E as centre and which passes through C. Click on the point E and then on point C.
03:18 We see that the circle will passes through all the vertices of the quadrilateral.A Cyclic Quadrilateral is drawn.
03:29 Do you know , that the cyclic quadrilateral has maximum area among all the quadrilaterals of the same sequence of side lengths.
03:37 Let's use the "Move" tool, to animate the figure.
03:42 To do this Let's select the Move tool from the tool bar, click on the Move tool place the mouse pointer on A or B. I will choose A
03:52 Place the mouse pointer on A and drag it with the mouse to animate.
03:58 To verify that the construction is correct.
04:01 Let's now save the file.
04:04 Click on File Save As.
04:07 I will type the file name as cyclic_quadrilateral
04:21 and click on save
04:23 Let us now open a new geogebra window to construct an incircle.
04:28 To do this Let's select on File and New.
04:35 Let's now construct a triangle to do this , Let's select the Polygon tool from the tool bar, Click on the Polygon tool.
04:44 click on the points A,B,C and A once again to complete the triangle figure.
04:52 Let's measure the angles for this triangle,
04:55 To do this Let's select the Angle tool from the tool bar, click on the Angle tool.
05:00 Click on the points B,A,C , C,B,A and A,C,B.
05:15 We see that the angles are measured.
05:18 Lets now construct angle bisectors to these angles.
05:21 Select the Angle bisector tool from the tool bar,
05:25 click on the Angle bisector tool.Click on the points B,A,C .
05:32 Let's select the Angle bisector tool again from the tool bar to construct second angle bisector.
05:39 click on the Angle bisector tool and the tool bar, click on the points A,B,C.
05:48 We see that the two angle bisectors intersect at point .
05:52 Let's mark this point as D.
05:55 Let's now construct a perpendicular line which passes through point D and segment AB.
06:02 Select perpendicular line tool from tool bar,click on the perpendicular line tool, click on the point D and then on segment AB.
06:12 We see that the perpendicular line intersects segment AB at a point.
06:17 Let's mark this point as E.
06:20 Let's now construct a circle with centre as D and which passes through E.
06:27 Let's select the compass tool from tool bar , click on the compass tool,click on the point D as centre and DE as radius.
06:37 Click on the point D and then on point E and D once again to complete the figure.
06:46 We see that the circle touches all the sides of the triangle.
06:50 An in-circle is drawn.
06:53 With this we come to an end of this tutorial.


06:57 To Summarize
07:02 In this tutorial we have learnt to construct
07:05 cyclic quadrilateral and
07:07 In-circle using the Geogebra tools.
07:10 As an assignment i would like you to draw a triangle ABC
07:15 Mark a point D on BC, join AD
07:19 Draw in-circles form triangles ABC, ABD and CBD of radii r, r1 and r2 .
07:28 BE is the height h
07:30 Move the vertices of the Triangle ABC
07:33 To verify the relation.
07:35 (1 -2r1/h)*(1 - 2r2/h) = (1 -2r/h)
07:43 The output of the assignment should look like this.
07:52 Watch the video available at this URL.
07:55 It summarises the Spoken Tutorial project.
07:57 If you do not have good bandwidth, you can download

and watch it

08:02 The Spoken Tutorial Project Team :Conducts workshops using spoken tutorials.
08:06 Gives certificates to those who pass an online test
08:09 For more details, contact us contact@spoken-tutorial.org
08:16 Spoken Tutorial Project is a part of Talk to a Teacher project
08:19 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
08:25 More information on this Mission is available at this link.
08:29 This is Madhuri Ganapathi from IIT Bombay signing off

Thanks for joining.

Contributors and Content Editors

Madhurig, Minal, Nancyvarkey, PoojaMoolya, Pratik kamble, Sandhya.np14

Retrieved from "https://script.spoken-tutorial.org/index.php?title=Geogebra/C3/Relationship-between-Geometric-Figures/English-timed&oldid=16423"