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{| border=1
 
{| border=1
!'''Time'''
+
|'''Time'''
!'''Narration'''
+
|'''Narration'''
 
|-
 
|-
 
|00:00
 
|00:00
|Hello everybody.Welcome to this tutorial on Symmetrical Transformation in Geogebra  
+
|Hello everybody. Welcome to this tutorial on '''Symmetrical Transformation''' in '''Geogebra'''.
  
 
|-
 
|-
 
|00:06
 
|00:06
|In this tutorial we will learn Symmetrical transformations such as
+
|In this tutorial we will learn Symmetrical transformations such as:
  
 
|-
 
|-
 
|00:11
 
|00:11
|Line symmetry  
+
| Line symmetry Rotation symmetry  
 
+
|-
+
|00:12
+
|Rotation symmetry  
+
  
 
|-
 
|-
 
|00:13
 
|00:13
|and also learn to
+
|and also learn to enlarge figure with scale and position.
Enlarge figure with scale and position  
+
  
 
|-
 
|-
 
|00:17
 
|00:17
|We assume that you have the basic working knowledge of Geogebra
+
|We assume that you have the basic working knowledge of Geogebra.
  
 
|-
 
|-
 
|00:21
 
|00:21
|If not, For relevant tutorials, Please visit our website
+
|If not, for relevant tutorials, please visit our website.
  
 
|-
 
|-
 
|00:26
 
|00:26
|To record this tutorial I am using
+
|To record this tutorial, I am using '''Ubuntu Linux OS Version 11.10''',
Ubuntu Linux OS Version 11.10
+
  
 
|-
 
|-
 
|00:31
 
|00:31
|Geogebra Version 3.2.47.0  
+
|'''Geogebra Version 3.2.47.0'''.
  
 
|-
 
|-
 
|00:35
 
|00:35
|We will use the following Geogebra tools
+
|We will use the following Geogebra tools:
  
 
|-
 
|-
Line 62: Line 56:
 
|-
 
|-
 
|00:47
 
|00:47
|Regular Polygon and  
+
| Regular Polygon and  
  
 
|-
 
|-
Line 70: Line 64:
 
|-
 
|-
 
|00:51
 
|00:51
|Definition of Transformation
+
|Definition of '''Transformation'''-
  
 
|-
 
|-
 
|00:53
 
|00:53
|Symmetrical transformation of a geometric figure is -
+
|Symmetrical transformation of a geometric figure is:
  
 
|-
 
|-
 
|00:57
 
|00:57
|A change in its position, size or shape on a coordinate plane
+
| A change in its position, size or shape on a coordinate plane.
  
 
|-
 
|-
 
|01:02
 
|01:02
|Original figure is called '''Object'''
+
| Original figure is called '''Object'''.
  
 
|-
 
|-
 
|01:04
 
|01:04
|Transformed figure is called '''Image'''  
+
| Transformed figure is called '''Image'''.
  
 
|-
 
|-
 
|01:07
 
|01:07
|Reflection symmetry
+
|'''Reflection symmetry''':
  
 
|-
 
|-
 
|01:09
 
|01:09
|Is also called as Line symmetry
+
| Is also called as '''Line symmetry'''.
  
 
|-
 
|-
 
|01:11
 
|01:11
|A type of symmetry where one half is the reflection of the other half
+
|A type of symmetry where one half is the reflection of the other half.
  
 
|-
 
|-
 
|01:15
 
|01:15
|You could fold the image and have both halves match exactly  
+
|You could fold the image and have both halves match exactly.
  
 
|-
 
|-
Line 110: Line 104:
 
|-
 
|-
 
|01:24
 
|01:24
|Let's Switch to GeoGebra window
+
|Let's switch to Geogebra window.
  
 
|-
 
|-
 
|01:27
 
|01:27
|Look on Dash home >>Media Apps>>Under Type >>Choose Education>> and Geogebra
+
|Look on '''Dash home''' >> '''Media Apps''' >> under '''Type''' >> choose '''Education''' >> and '''Geogebra'''.
  
 
|-
 
|-
 
|01:37
 
|01:37
|For this tutorial I am closing the Algebric view
+
|For this tutorial, I am closing the '''Algebric view'''.
  
 
|-
 
|-
 
|01:40
 
|01:40
|Click on Close button on Algebric view
+
|Click on Close button on '''Algebric view'''.
  
 
|-
 
|-
 
|01:47
 
|01:47
|Let's start with '''Line of symmetry'''
+
|Let's start with '''Line of symmetry'''.
  
 
|-
 
|-
 
|01:50
 
|01:50
|First let's construct an equilateral triangle.
+
|First, let's construct an equilateral triangle.
  
 
|-
 
|-
 
|01:53
 
|01:53
|Select “Regular Polygon” tool from the toolbar.  
+
|Select '''Regular Polygon''' tool from the toolbar.  
  
 
|-
 
|-
Line 142: Line 136:
 
|-
 
|-
 
|02:08
 
|02:08
|An equilateral triangle '''ABC''' is drawn  
+
|An equilateral triangle '''ABC''' is drawn.
  
 
|-
 
|-
 
|02:11
 
|02:11
|Let's draw a perpendicular bisector to one of the sides of triangle
+
|Let's draw a perpendicular bisector to one of the sides of triangle.
  
 
|-
 
|-
 
|02:15
 
|02:15
|Select '''Perpendicular Bisector Tool''' and click on side AC  
+
|Select '''Perpendicular Bisector Tool''' and click on side AC.
  
 
|-
 
|-
 
|02:26
 
|02:26
|Select the Point tool and create a point inside the triangle.
+
|Select the '''Point''' tool and create a point inside the triangle.
  
 
|-
 
|-
Line 162: Line 156:
 
|-
 
|-
 
|02:38
 
|02:38
|Right click on point D and select Trace ON
+
|Right click on point D and select '''Trace On'''.
  
 
|-
 
|-
 
|02:43
 
|02:43
|Select '''Reflect Object about Line'''tool from the tool bar  
+
|Select '''Reflect Object about Line''' tool from the tool bar.
  
 
|-
 
|-
 
|02:48
 
|02:48
|Click on the point D
+
|Click on the point D.This will highlight point D.
 
+
|-
+
|02:49
+
|This will highlight Point D
+
  
 
|-
 
|-
 
|02:52
 
|02:52
|Click on perpendicular Bisector
+
|Click on '''Perpendicular Bisector'''.
  
 
|-
 
|-
 
|02:55
 
|02:55
|This will produce reflected image D' on the other side of perpendicular bisector  
+
|This will produce reflected image D' on the other side of perpendicular bisector.
  
 
|-
 
|-
 
|03:01
 
|03:01
|'''D''' is mirror image of point '''D'''
+
|'''D' '''is mirror image of point '''D'''.
  
 
|-
 
|-
 
|03:04
 
|03:04
|Set Trace On for the point '''D'''
+
|Set '''Trace On''' for the point '''D'''.
 
 
 
|-
 
|-
 
|03:08
 
|03:08
|Let us move the point D along the triangle using Move tool
+
|Let us move the point D along the triangle, using '''Move''' tool.
  
 
|-
 
|-
 
|03:11
 
|03:11
|Click on the first option under Move tool from the toolbar
+
|Click on the first option under '''Move''' tool from the toolbar.
  
 
|-
 
|-
Line 214: Line 204:
 
|-
 
|-
 
|03:31
 
|03:31
|What do you notice ?
+
|What do you notice ? Here perpendicular bisector is the line of symmetry.
 
+
|-
+
|03:32
+
|Here perpendicular bisector is the line of symmetry
+
  
 
|-
 
|-
 
|03:36
 
|03:36
|D is the object and '''D''' is the image
+
|'''D''' is the object and '''D' '''is the image.
 
 
 
|-
 
|-
 
|03:39
 
|03:39
|Let's reflect a semicircle about a line
+
|Let's reflect a semicircle about a line.
  
 
|-
 
|-
 
|03:43
 
|03:43
|Let's draw a semicircle
+
|Let's draw a semicircle.Click on the '''Semicircle through Two points''' tool. Mark point E and then F.
 
+
|-
+
|03:44
+
|Click on the '''Semicircle through Two points''' tool Mark point E and then F  
+
  
 
|-
 
|-
 
|03:56
 
|03:56
|Click on segment Between two Points
+
|Click on segment between two points.
  
 
|-
 
|-
 
|04:02
 
|04:02
|Mark points G and H A line is drawn  
+
|Mark points G and H. A line is drawn.
  
 
|-
 
|-
 
|04:06
 
|04:06
|Let's change the property of the line
+
|Let's change the property of the line.
  
 
|-
 
|-
|4:08
+
|04:08
|Right click on the line Object properties Click on Style change Style  
+
|Right click on the line, '''Object Properties'''. Click on '''Style''', change Style.
  
 
|-
 
|-
 
|04:21
 
|04:21
|Select '''Reflect Object about Line''' tool from the toolbar
+
|Select '''Reflect Object about Line''' tool from the toolbar.
  
 
|-
 
|-
 
|04:27
 
|04:27
|Click on the semicircle EF
+
|Click on the semicircle EF.
  
 
|-
 
|-
 
|04:31
 
|04:31
|Click on line GH
+
|Click on line GH.
  
 
|-
 
|-
 
|04:34
 
|04:34
|This will produce the reflected image E'F' on the other side of line GH What does the figure look like now ? It looks like a circle  
+
|This will produce the reflected image E'F' on the other side of line GH. What does the figure look like now ? It looks like a circle.
  
 
|-
 
|-
 
|04:45
 
|04:45
|Let us save this file now
+
|Let us save this file now.
  
 
|-
 
|-
 
|04:47
 
|04:47
|Click on '''File'''>> '''Save As'''
+
|Click on '''File''' '''Save As'''.
  
 
|-
 
|-
 
|04:50
 
|04:50
|I will type the file name as '''Line-symmetry''' and click on '''Save'''
+
|I will type the file name as '''Line-symmetry''' and click on '''Save'''.
 
 
 
|-
 
|-
 
|05:05
 
|05:05
|Next, let us learn to '''Rotate the Object around a Point by Angle'''
+
|Next, let us learn to '''Rotate the Object around a Point by Angle'''.
  
 
|-
 
|-
 
|05:12
 
|05:12
|Definition of Rotation
+
|Definition of Rotation-
  
 
|-
 
|-
 
|05:15
 
|05:15
|A rotation is a transformation that turns a figure around a fixed center by an angle
+
|A rotation is a transformation that turns a figure around a fixed center by an angle.
  
 
|-
 
|-
 
|05:21
 
|05:21
|If the figure appears unchanged, then the figure has rotation symmetry
+
|If the figure appears unchanged then the figure has rotation symmetry.
  
 
|-
 
|-
 
|05:29
 
|05:29
|You can rotate object at any degree measure Rotation can be clockwise and counterclockwise  
+
|You can rotate object at any degree measure. Rotation can be clockwise and counterclockwise.
  
 
|-
 
|-
 
|05:39
 
|05:39
|Let's open a new Geogebra window
+
|Let's open a new Geogebra window.
  
 
|-
 
|-
 
|05:41
 
|05:41
|click on '''File''' >> New
+
|click on '''File''' '''New'''.
  
 
|-
 
|-
Line 314: Line 296:
 
|-
 
|-
 
|05:49
 
|05:49
|click on '''Regular Polygon''' tool from the toolbar  
+
|click on '''Regular Polygon''' tool from the toolbar.
  
 
|-
 
|-
 
|05:55
 
|05:55
|Click on the drawing pad
+
|Click on the drawing pad.
  
 
|-
 
|-
 
|05:57
 
|05:57
|Mark points '''A''' and '''B'''  
+
|Mark points '''A''' and '''B'''.
  
 
|-
 
|-
 
|05:59
 
|05:59
|A dialog box opens
+
|A dialog box opens.
  
 
|-
 
|-
 
|06:01
 
|06:01
|Click on OK
+
|Click on '''OK'''.
  
 
|-
 
|-
 
|06:03
 
|06:03
|A square '''ABCD''' is drawn  
+
|A square '''ABCD''' is drawn.
  
 
|-
 
|-
 
|06:05
 
|06:05
|Click on '''Rotate Object around a Point by Angle''' tool
+
|Click on '''Rotate Object around a Point by Angle''' tool.
  
 
|-
 
|-
 
|06:13
 
|06:13
|Click on the Square '''ABCD'''
+
|Click on the Square '''ABCD'''.
  
 
|-
 
|-
 
|06:16
 
|06:16
|This will highlight the square
+
|This will highlight the square.
  
 
|-
 
|-
 
|06:18
 
|06:18
|Next Click on any one of the vertices
+
|Next Click on any one of the vertices.
  
 
|-
 
|-
 
|06:20
 
|06:20
|I will click on '''A'''
+
|I will click on '''A'''.
  
 
|-
 
|-
 
|06:23
 
|06:23
|A dialog box opens
+
|A dialog box opens.
  
 
|-
 
|-
 
|06:25
 
|06:25
|Type '''60''' in the Angle field
+
|Type '''60''' in the '''Angle''' field
  
 
|-
 
|-
 
|06:30
 
|06:30
|Select '''"°"''' from first drop down list
+
|Select '''°'''(Degree) from first drop down list.
  
 
|-
 
|-
 
|06:35
 
|06:35
|Select the option '''clockwise'''
+
|Select the option '''clockwise'''. Click on '''OK'''.
Click on OK
+
  
 
|-
 
|-
 
|06:40
 
|06:40
|This will rotate the square clockwise at the point of selection with the angle of 60°
+
|This will rotate the square clockwise at the point of selection, with the angle of 60°.
  
 
|-
 
|-
 
|06:44
 
|06:44
|The rotated image 'A`B`C` 'D' is formed
+
|The rotated image '''A`B`C`D`''' is formed.
 
 
 
|-
 
|-
 
|06:49
 
|06:49
|Let's move this figure aside using Move tool
+
|Let's move this figure aside using '''Move''' tool.
  
 
|-
 
|-
 
|07:00
 
|07:00
|Next, let's '''Dilate or enlarge object from point by factor'''  
+
|Next, let's '''dilate''' or '''enlarge object from point by factor.'''  
  
 
|-
 
|-
 
|07:09
 
|07:09
|Dilation
+
|'''Dilation''':
  
 
|-
 
|-
Line 399: Line 380:
 
|-
 
|-
 
|07:14
 
|07:14
|in which a figure is enlarged using a scale factor  
+
|in which a figure is enlarged using a scale factor.
  
 
|-
 
|-
 
|07:23
 
|07:23
|Let's draw a triangle Using the '''Polygon'''tool
+
|Let's draw a triangle using the '''Polygon'''tool,
  
 
|-
 
|-
 
|07:28
 
|07:28
|E , F , G click on E again to complete the triangle  
+
|E , F , G. Click on E again to complete the triangle.
  
 
|-
 
|-
 
|07:36
 
|07:36
|Click on New point tool and
+
|Click on '''New Point''' tool and
  
 
|-
 
|-
 
|07:40
 
|07:40
|Mark a point '''H'''  
+
|mark a point '''H'''.
  
 
|-
 
|-
 
|07:44
 
|07:44
|Click on '''Dilate Object from Point by Factor''' tool  
+
|Click on '''Dilate Object from Point by Factor''' tool.
  
 
|-
 
|-
 
|07:51
 
|07:51
|Click on the triangle '''EFG'''
+
|Click on the triangle '''EFG'''.
  
 
|-
 
|-
 
|07:54
 
|07:54
|This will highlight the triangle  
+
|This will highlight the triangle.
  
 
|-
 
|-
 
|07:55
 
|07:55
|Click on the point 'H'
+
|Click on the point 'H'.
  
 
|-
 
|-
 
|07:57
 
|07:57
|A dialog box opens
+
|A dialog box opens.
  
 
|-
 
|-
 
|08:00
 
|08:00
|Type value of 2 in the number field
+
|Type value of 2 in the number field.
  
 
|-
 
|-
 
|08:04
 
|08:04
|Click on OK
+
|Click on '''OK'''.
 
 
 
|-
 
|-
 
|08:09
 
|08:09
|This will dilate or enlarge the object twice
+
|This will dilate or enlarge the object twice.
  
 
|-
 
|-
 
|08:16
 
|08:16
|Click on Segment Between two Points, join points H,E,E'  
+
|Click on segment between two Points, join points H,E,E'.
  
 
|-
 
|-
 
|08:33
 
|08:33
|join points H,G,G'  
+
|join points H,G,G'.
  
 
|-
 
|-
 
|09:01
 
|09:01
|join points H,F,F'
+
|join points H,F,F'.
 
 
 
|-
 
|-
 
|09:15
 
|09:15
|Here you can see that H is the point of dilation
+
|Here, you can see that H is the point of dilation.
  
 
|-
 
|-
 
|09:21
 
|09:21
|You can enlarge object as number of times as you wish, by typing the value of Factor  
+
|You can enlarge object as many number of times as you wish, by typing the value of '''Factor'''.
  
 
|-
 
|-
 
|09:28
 
|09:28
|Let us save this file now
+
|Let us save this file now.
  
 
|-
 
|-
 
|09:30
 
|09:30
|Click on '''File'''>> '''Save As'''
+
|Click on '''File''' >> '''Save As'''.
  
 
|-
 
|-
 
|09:33
 
|09:33
|I will type the file name as '''Dilate-triangle'''
+
|I will type the file name as '''Dilate-triangle'''.
  
 
|-
 
|-
 
|09:48
 
|09:48
|Click on '''Save''' with this we come to the end of this tutorial  
+
|Click on '''Save'''. With this we come to the end of this tutorial.
  
 
|-
 
|-
 
|09:55
 
|09:55
|Let's summarize
+
|Let's summarize.
  
 
|-
 
|-
 
|09:58
 
|09:58
|In this tutorial we learnt
+
|In this tutorial we learnt:
  
 
|-
 
|-
 
|10:00
 
|10:00
|Reflection about a line  
+
|Reflection about a line.
  
 
|-
 
|-
 
|10:02
 
|10:02
|Rotation of an object at a point  
+
|Rotation of an object at a point.
  
 
|-
 
|-
 
|10:05
 
|10:05
|Enlargement of an object by a scale factor  
+
| Enlargement of an object by a scale factor.
  
 
|-
 
|-
 
|10:09
 
|10:09
|As an assignment I would like you to
+
|As an assignment I would like you to:
  
 
|-
 
|-
 
|10:11
 
|10:11
|Draw a Pentagon
+
|Draw a pentagon.Use '''Regular Polygon''' tool to draw. (Hint:sides=5).
 
+
|-
+
|10:12
+
|Use Regular Polygon tool to draw(Hint:sides=5)
+
  
 
|-
 
|-
 
|10:17
 
|10:17
|Draw a Perpendicular bisector to one of the sides of the pentagon
+
|Draw a perpendicular bisector to one of the sides of the pentagon.
  
 
|-
 
|-
 
|10:21
 
|10:21
|Create a point in side the pentagon
+
|Create a point inside the pentagon.
  
 
|-
 
|-
 
|10:25
 
|10:25
|Set trace On for the point
+
|Set '''Trace On''' for the point.
  
 
|-
 
|-
 
|10:27
 
|10:27
|Get reflection of the point about the perpendicular bisector
+
|Get reflection of the point about the perpendicular bisector.
  
 
|-
 
|-
 
|10:31
 
|10:31
|Set trace On for the image point
+
|Set '''Trace On''' for the image point.
  
 
|-
 
|-
 
|10:34
 
|10:34
|Trace the pentagon to see if you have selected the correct line of symmetry
+
|Trace the pentagon to see if you have selected the correct line of symmetry.
  
 
|-
 
|-
 
|10:44
 
|10:44
|Rotate the original pentagon counter clockwise in 135° at a point
+
|Rotate the original pentagon counter clockwise in 135° at a point.
  
 
|-
 
|-
 
|10:49
 
|10:49
|Dilate the pentagon at a point by the factor of 3
+
|Dilate the pentagon at a point by the factor of 3.
  
 
|-
 
|-
 
|10:56
 
|10:56
|The assignment should look like this
+
|The assignment should look like this.
  
 
|-
 
|-
 
|11:03
 
|11:03
|Watch the video available at this URL
+
|Watch the video available at this URL.
  
 
|-
 
|-
 
|11:06
 
|11:06
|It summarises the Spoken Tutorial project
+
|It summarizes the Spoken Tutorial project.
  
 
|-
 
|-
 
|11:09
 
|11:09
|If you do not have good bandwidth,you can download and watch it
+
|If you do not have good bandwidth,you can download and watch it.
 
 
 
|-
 
|-
 
|11:12
 
|11:12
|The Spoken Tutorial Project Team :
+
|The Spoken Tutorial Project Team : Conducts workshops using the spoken tutorials.
Conducts workshops using the spoken tutorials
+
  
 
|-
 
|-
 
|11:17
 
|11:17
|Gives certificates to those who pass an online test
+
|Gives certificates to those who pass an online test.
  
 
|-
 
|-
 
|11:20
 
|11:20
|For more details, please write to
+
|For more details, please write to contact@spoken-tutorial.org.
contact@spoken-tutorial.org
+
  
 
|-
 
|-
 
|11:26
 
|11:26
|Spoken Tutorial Project is a part of the Talk to a Teacher project
+
|Spoken Tutorial Project is a part of the Talk to a Teacher project.
  
 
|-
 
|-
 
|11:29
 
|11:29
|It is supported by the National Mission on Education through ICT, MHRD, Government of India
+
|It is supported by the National Mission on Education through ICT, MHRD, Government of India.
  
 
|-
 
|-
Line 593: Line 568:
 
|-
 
|-
 
|11:39
 
|11:39
|This is Neeta Sawant from SNDT University Mumbai signing off.
+
|This is Neeta Sawant from SNDT University Mumbai, signing off.Thanks for joining.
  
Thanks for joining
+
|}

Latest revision as of 18:02, 7 March 2017

Time Narration
00:00 Hello everybody. Welcome to this tutorial on Symmetrical Transformation in Geogebra.
00:06 In this tutorial we will learn Symmetrical transformations such as:
00:11 Line symmetry Rotation symmetry
00:13 and also learn to enlarge figure with scale and position.
00:17 We assume that you have the basic working knowledge of Geogebra.
00:21 If not, for relevant tutorials, please visit our website.
00:26 To record this tutorial, I am using Ubuntu Linux OS Version 11.10,
00:31 Geogebra Version 3.2.47.0.
00:35 We will use the following Geogebra tools:
00:37 Reflect Object about Line
00:39 Rotate Object around Point by Angle
00:42 Dilate object from a Point by Factor
00:45 Semicircle through Two points
00:47 Regular Polygon and
00:49 Perpendicular bisector
00:51 Definition of Transformation-
00:53 Symmetrical transformation of a geometric figure is:
00:57 A change in its position, size or shape on a coordinate plane.
01:02 Original figure is called Object.
01:04 Transformed figure is called Image.
01:07 Reflection symmetry:
01:09 Is also called as Line symmetry.
01:11 A type of symmetry where one half is the reflection of the other half.
01:15 You could fold the image and have both halves match exactly.
01:20 Line of Symmetry is the line over which the figure is reflected.
01:24 Let's switch to Geogebra window.
01:27 Look on Dash home >> Media Apps >> under Type >> choose Education >> and Geogebra.
01:37 For this tutorial, I am closing the Algebric view.
01:40 Click on Close button on Algebric view.
01:47 Let's start with Line of symmetry.
01:50 First, let's construct an equilateral triangle.
01:53 Select Regular Polygon tool from the toolbar.
01:57 Click on drawing pad points A ,B, and enter 3 for the number of sides.
02:08 An equilateral triangle ABC is drawn.
02:11 Let's draw a perpendicular bisector to one of the sides of triangle.
02:15 Select Perpendicular Bisector Tool and click on side AC.
02:26 Select the Point tool and create a point inside the triangle.
02:31 Move the point D towards one of the vertices .
02:38 Right click on point D and select Trace On.
02:43 Select Reflect Object about Line tool from the tool bar.
02:48 Click on the point D.This will highlight point D.
02:52 Click on Perpendicular Bisector.
02:55 This will produce reflected image D' on the other side of perpendicular bisector.
03:01 D' is mirror image of point D.
03:04 Set Trace On for the point D.
03:08 Let us move the point D along the triangle, using Move tool.
03:11 Click on the first option under Move tool from the toolbar.
03:22 Click on figure with the mouse.
03:25 Drag it tracing the triangle .
03:28 Now release the mouse button.
03:31 What do you notice ? Here perpendicular bisector is the line of symmetry.
03:36 D is the object and D' is the image.
03:39 Let's reflect a semicircle about a line.
03:43 Let's draw a semicircle.Click on the Semicircle through Two points tool. Mark point E and then F.
03:56 Click on segment between two points.
04:02 Mark points G and H. A line is drawn.
04:06 Let's change the property of the line.
04:08 Right click on the line, Object Properties. Click on Style, change Style.
04:21 Select Reflect Object about Line tool from the toolbar.
04:27 Click on the semicircle EF.
04:31 Click on line GH.
04:34 This will produce the reflected image E'F' on the other side of line GH. What does the figure look like now ? It looks like a circle.
04:45 Let us save this file now.
04:47 Click on File Save As.
04:50 I will type the file name as Line-symmetry and click on Save.
05:05 Next, let us learn to Rotate the Object around a Point by Angle.
05:12 Definition of Rotation-
05:15 A rotation is a transformation that turns a figure around a fixed center by an angle.
05:21 If the figure appears unchanged then the figure has rotation symmetry.
05:29 You can rotate object at any degree measure. Rotation can be clockwise and counterclockwise.
05:39 Let's open a new Geogebra window.
05:41 click on File New.
05:47 Let us construct a square.
05:49 click on Regular Polygon tool from the toolbar.
05:55 Click on the drawing pad.
05:57 Mark points A and B.
05:59 A dialog box opens.
06:01 Click on OK.
06:03 A square ABCD is drawn.
06:05 Click on Rotate Object around a Point by Angle tool.
06:13 Click on the Square ABCD.
06:16 This will highlight the square.
06:18 Next Click on any one of the vertices.
06:20 I will click on A.
06:23 A dialog box opens.
06:25 Type 60 in the Angle field
06:30 Select °(Degree) from first drop down list.
06:35 Select the option clockwise. Click on OK.
06:40 This will rotate the square clockwise at the point of selection, with the angle of 60°.
06:44 The rotated image A`B`C`D` is formed.
06:49 Let's move this figure aside using Move tool.
07:00 Next, let's dilate or enlarge object from point by factor.
07:09 Dilation:
07:11 Dilation or enlargement is a transformation
07:14 in which a figure is enlarged using a scale factor.
07:23 Let's draw a triangle using the Polygontool,
07:28 E , F , G. Click on E again to complete the triangle.
07:36 Click on New Point tool and
07:40 mark a point H.
07:44 Click on Dilate Object from Point by Factor tool.
07:51 Click on the triangle EFG.
07:54 This will highlight the triangle.
07:55 Click on the point 'H'.
07:57 A dialog box opens.
08:00 Type value of 2 in the number field.
08:04 Click on OK.
08:09 This will dilate or enlarge the object twice.
08:16 Click on segment between two Points, join points H,E,E'.
08:33 join points H,G,G'.
09:01 join points H,F,F'.
09:15 Here, you can see that H is the point of dilation.
09:21 You can enlarge object as many number of times as you wish, by typing the value of Factor.
09:28 Let us save this file now.
09:30 Click on File >> Save As.
09:33 I will type the file name as Dilate-triangle.
09:48 Click on Save. With this we come to the end of this tutorial.
09:55 Let's summarize.
09:58 In this tutorial we learnt:
10:00 Reflection about a line.
10:02 Rotation of an object at a point.
10:05 Enlargement of an object by a scale factor.
10:09 As an assignment I would like you to:
10:11 Draw a pentagon.Use Regular Polygon tool to draw. (Hint:sides=5).
10:17 Draw a perpendicular bisector to one of the sides of the pentagon.
10:21 Create a point inside the pentagon.
10:25 Set Trace On for the point.
10:27 Get reflection of the point about the perpendicular bisector.
10:31 Set Trace On for the image point.
10:34 Trace the pentagon to see if you have selected the correct line of symmetry.
10:44 Rotate the original pentagon counter clockwise in 135° at a point.
10:49 Dilate the pentagon at a point by the factor of 3.
10:56 The assignment should look like this.
11:03 Watch the video available at this URL.
11:06 It summarizes the Spoken Tutorial project.
11:09 If you do not have good bandwidth,you can download and watch it.
11:12 The Spoken Tutorial Project Team : Conducts workshops using the spoken tutorials.
11:17 Gives certificates to those who pass an online test.
11:20 For more details, please write to contact@spoken-tutorial.org.
11:26 Spoken Tutorial Project is a part of the Talk to a Teacher project.
11:29 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
11:35 More information on this Mission is available at this link.
11:39 This is Neeta Sawant from SNDT University Mumbai, signing off.Thanks for joining.

Contributors and Content Editors

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