Geogebra/C3/Mensuration/English
Title of script: Mensuration in Geogebra
Author: Madhuri Ganapathi
Keywords: Segment between two points, Circle with center and radius, Ellipse, Polygon, New point and Center, Insert text Area, Perimeter, Surface area, Volume, concatenation, Text box, input bar, video tutorial.
Visual Cue  Narration 

Slide Number 1  Hello everybody
Welcome to this tutorial on Mensuration in Geogebra. 
Slide number 2
Learning Objectives 
In this tutorial, we will learn to find

Slide number 3
Prerequisites 
We assume that you have the basic working knowledge of Geogebra.
For Revelant tutorials on Geogebra, Please visit our website 
Slide Number 4
System Requirement 
To record this tutorial I am using Ubuntu Linux OS Version 11.10 Geogebra Version 3.2.47.0 
Slide Number 5
Tools used in the tutorial 
We will use the following Geogebra tools

Switch to Geogebra window
Dash home>> Media Apps>>Eduaction>>Geogebra 
Let's open a new Geogebra window.
Click on Dash home and Media Apps. Under Type, choose Education and Geogebra 
Let's find the area of a rhombus.
Let's use the file quadrilateral.ggb of the previous tutorial  
“File”>>Open”>>rhombus.ggb  Click on File, Open click on quadrilateral.ggb
click on 'Open' 
Area of the Rhombus =1/2 * product of diagonals  Area of the Rhombus =1/2 * product of diagonals 
To demonstrate it  
Click “Insert text” tool  Click on the “Insert text” tool 
Click on the drawing pad  
“Area of rhombus=" + (1 / 2 g f)  A text box opens
“Area of the rhombus =”+(1/2 g f) 
In the text box type  Open the double quotes(“) type
Area of the rhombus = close the double quotes '+' for concatenation open the brackets type '1/2' space 'f' space 'g' close the bracket 'f' and 'g' are diagonals of the rhombus 
Click Ok.
Point to the Area of rhombus 
Click Ok.
Area of rhombus is displayed here on the drawing pad. 
Click “Insert text” tool 
Next, let's find Perimeter
Click on the “Insert text” tool 
Click on the drawing pad.  Click on the drawing pad. 
“Perimeter of the rhombus =”+(4a)  A text box opens.
“Perimeter of the rhombus =”+(4 a) 
In the text box type  Open the double quotes(“) type
Perimeter of the rhombus = close double quotes '+' open the brackets '4' space 'a' close the brackets 'a' is side of the rhombus 
Click Ok.
Point to perimeter of rhombus 
Click Ok.
Perimeter of rhombus is displayed here on the drawing pad. 
Click on "Save As" >> type "rhombusareaperimeter" in filename >> click on Save  Lets save this file now.
Click on “File” and "Save As". I will type the filename as "rhombusareaperimeter" Click on “Save”. 
Slide Number 6
Assignment 1 
To find area and perimeter of trapezium, use output of file “constrapezium.ggb” Rename object 'g' as 'b' Formula for area = (half sum of parallel sides) * (vertical height) = (a+b)/2* h Formula for perimeter =(sum of the sides) =(a+b+c+d) 
Show the output of the Assignment  The output of the assignment should look like this. 
Click on “File” >> “New”  Let's open a new Geogebra window to draw a sphere
Click on “File” , “New” 
Click “Circle with center and radius” tool  Click on “Circle with center and radius” tool from the toolbar 
Click on the drawing pad point 'A'  
Dialog box opens >>type value '2' for the radius  A text box opens.
enter value '2' for radius. 
Click OK  Click OK
A circle with center 'A' and radius '2cm' is drawn. 
Click New point tool >>mark point 'B'  Select “New point” tool from tool bar mark a point 'B' on the circumference of the circle 
Click “Segment between two points” tool>> join 'A' and 'B' 
Select “Segment between two points” tool
Join points 'A' and 'B' as radius of the circle 
Let's draw an ellipse “CDE” in the horizontal direction,
to touch the circumference of the circle.  
Click “Ellipse” tool>>touch the circumference  Click on “Ellipse” tool from tool bar 
Mark points 'C' , 'D' 'E'  Mark points 'C' and 'D' diagonally opposite to each other on the circumference
and a third point 'E' inside the circle Here a sphere is drawn 
Click on “Insert text” tool 
Let's now find the Surface area of the sphere
Click on “Insert text” tool 
Click on the drawing pad.  Click on the drawing pad. 
Scroll down the list to find π (pi) 
A text box opens
Please use drop down list in the text box for special characters Scroll down the list to find π (pi) 
Type in the text box >>
“ Surface area of the sphere =” +( 4 π a^2) 
“ Surface area of a sphere =” +( 4 π a2) 
Type in the text box  open double quote type
Surface area of the sphere = close double quote 'plus' open the bracket '4' space select 'π' from the list space 'a' select 'square' from the list close the bracket 
Click OK  Click OK
surface area of the sphere is displayed here let me click on it and drag it place it below 
Next let's find Volume  
Insert another text box 
Click on the 'Insert Text' tool 
click on the drawing pad
Text box opens  
Type in text box >>“Volume of the sphere =” +(4/3 π a^3)  “ Volume of the sphere =” +(4/3 π a^3) 
Type in the text box  open double quote type
Volume of the sphere = close double quote 'plus' open the bracket '4/3' space select 'π' from the list space 'a' select 'cube' from the list close the bracket 
click OK  click OK
Volume of the sphere is displayed here let me click on it and drag it to place it below 
Next let's draw a cone now  
Click Polygon tool>>Click on 'C' , 'D', 'F' and 'C' 
Click on “Polygon” tool
Click on points 'C' , 'D' and an external point 'F' and 'C'once again 
Click Segments between two points >> join points A and F  Select “Segments between two points” tool
to join points 'A' and 'F' We get height of the cone. 
Right click on the object>>select “Rename” Replace 'b with 'h' 
Let me rename object 'b' as 'h' which denotes height of the cone
Right click on object 'b' Click on “Rename” Replace 'b' with 'h' click OK 
Right click on the object>>select “Rename”>>replace c_1 with 's'  Let me also
Rename the object 'c_1' as 's' which denotes slant height of cone. Right click on 'c_1' click on “Rename” Replace 'c_1' with 's' Click OK 
Let's find now surface area and volume of the cone,
We can use either the Insert text tool from the tool bar or we can the input bar. I will use the “Input bar”  
Scroll down the list. Click on “π” 
Please find the special characters in the drop down list of “Input bar” Scroll down to find “π” 
Type in the input bar >> Area = (π a s + π a²)  Area = (π a s + π a²)
Type in the input bar 
Type in the 'Input bar'  Surfacearea = open the bracket
Select 'π' from the list space 'a' space 's' plus select 'π' from the list space 'a'
press enter

Point to the Algebra View  Area of the cone is displayed in the Algebra view
Please note when we use the Input bar answer appears in the Algebra view 
Let's find Volume  
Type in the input bar>>
Volume =(1/3 π a² b) 
Volume =(1/3 π a² h) 
Type in the 'Input bar'  Volume =open bracket
'1/3' space select 'π' from the list space 'a' Select 'square' from list space 'h' close the bracket Press enter 
Point to the Algebra view  Volume of the cone will be displayed here in the Algebra view 
Click on "Save As" >> type "Spherecone" in filename >> click on “Save”  Lets save this file now. Click on "Save As".
I will type the filename as "Spherecone" Click on “Save”. with this we come to the end of this tutorial 
Slide Number 7
Summary

Let us summarize
In this tutorial we have learnt to find
We have also learnt to draw sphere and cone 
Slide Number 8
Assignment 
Assignment
As an assignment I would like you to find Surface area and volume of cylinder Draw 2 same sized ellipses one below the other Connect edges of ellipses Use “center” tool, find center of one ellipse Join center and edge. Rename object 'b' as 'h' and 'e' as 'r' Surface area = 2 π r(r + h) Volume = π r^2h 
Show the output of the Assignment  The output of the assignment should look like this. 
Slide number 7
Acknowledgement 
Watch the video available at
http://spokentutorial.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@spokentutorial.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://spokentutorial.org/NMEICTIntro ] This is Madhuri Ganapathi from IIT Bombay signing off. Thanks for joining 