Difference between revisions of "Geogebra/C3/Mensuration/English-timed"
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Revision as of 15:30, 3 September 2014
Time | Narration |
00:00 | Hello everybody
Welcome to this tutorial on Mensuration in Geogebra. |
00:06 | In this tutorial, we will learn to find |
00:09 | Area and perimeter of rhombus |
00:12 | Surface area of sphere and cone |
00:15 | Volume of sphere and cone |
00:20 | We assume that you have the basic working knowledge of Geogebra. |
00:24 | For Relevant tutorials on Geogebra, |
00:27 | Please visit our website |
00:31 | To record this tutorial I am using |
00:33 | Ubuntu Linux OS Version 11.10 |
00:38 | Geogebra Version 3.2.47.0 |
00:42 | We will use the following Geogebra tools |
00:46 | Segment between two points |
00:48 | Circle with center and radius |
00:51 | Ellipse |
00:52 | Polygon |
00:54 | New point and |
00:56 | Insert text |
00:57 | Let's open a new Geogebra window. |
01:00 | Click on Dash home and Media Apps. Under Type, choose Education and Geogebra |
01:13 | Let's find the area of a rhombus. |
01:15 | Let's use the file quadrilateral.ggb of the previous tutorial |
01:20 | Click on File, Open click on quadrilateral.ggb |
01:27 | click on Open |
01:29 | Area of the Rhombus =1/2 * product of diagonals |
01:34 | To demonstrate it |
01:36 | Click on the Insert text tool |
01:39 | Click on the drawing pad
A text box opens |
01:44 | “Area of the rhombus =”+(1/2 g f)
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 the diagonals of the rhombus |
02:09 | Click Ok. |
02:11 | Area of rhombus is displayed here on the drawing pad. |
02:14 | Next, let's find Perimeter |
02:17 | Click on the Insert text tool |
02:19 | Click on the drawing pad.
A text box opens. |
02:22 | Open the double quotes(“) type
Perimeter of the rhombus =+(4 a) close double quotes '+' open the brackets 4 space 'a' close the brackets a is the side of the rhombus |
02:44 | Click Ok. |
02:46 | Perimeter of rhombus is displayed here on the drawing pad. |
02:50 | Let's now save the file. |
02:53 | Click on File and Save As. |
02:55 | I will type the filename as "rhombus-area-perimeter" |
03:12 | Click on Save. |
03:17 | As an assignment i would like you
To find area and perimeter of trapezium, |
03:22 | use output of file “cons-trapezium.ggb” |
03:27 | Rename object g as b |
03:30 | Formula for area = (half sum of parallel sides) * (vertical height) = (a+b)/2* h |
03:40 | Formula for perimeter =(sum of the sides) =(a+b+c+d) |
03:49 | The output of the assignment should look like this. |
03:54 | Let's open a new Geogebra window to draw a sphere |
03:58 | Click on File , New |
04:01 | Click on the Circle with center and radius tool from the toolbar |
04:06 | Click on the drawing pad point A
A text box opens. |
04:11 | enter value 2 for radius. |
04:13 | Click OK |
04:15 | A circle with center A and radius 2cm is drawn. |
04:19 | Select New point tool from tool bar mark a point 'B' on the circumference of the circle |
04:26 | Select Segment between two points tool |
04:29 | Join points A and B as radius of the circle |
04:34 | Let's draw an ellipse CDE in the horizontal direction,
to touch the circumference of the circle. |
04:42 | Click on Ellipse tool |
04:45 | Mark points C and D diagonally opposite to each other on the circumference
and a third point E inside the circle |
04:56 | Here a sphere is drawn |
04:59 | Let's now find the Surface area of the sphere |
05:03 | Click on Insert text tool |
05:05 | Click on the drawing pad.
A text box opens |
05:08 | Please find the special characters in the drop down list in the text box
Scroll down to find π (pi) |
05:17 | open double quote type
Surface area of the sphere = +( 4 π a2) close double quote 'plus' open the bracket '4' space select 'π' from the list space 'a' select 'square' from the list close the bracket |
05:45 | Click OK |
05:47 | surface area of the sphere is displayed here |
05:52 | let me click on it and drag it place it below |
05:56 | Next let's find Volume |
05:59 | Click on the 'Insert Text' tool |
06:00 | click on the drawing pad
Text box opens |
06:03 | open double quote type
Volume of the sphere = +(4/3 π a^3) 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 |
06:31 | click OK |
06:34 | Volume of the sphere is displayed here |
06:36 | let me click on it and drag it to place it below |
06:40 | Next let's draw a cone |
06:43 | Click on Polygon tool |
06:45 | Click on points C , D and an external point F
and C once again |
06:53 | Select “Segments between two points” tool
join points F and A |
06:59 | We get height of the cone.
|
07:03 | Let me rename the object b as h which denotes height of the cone |
07:08 | Right click on object b |
07:09 | Click on Rename |
07:11 | Replace b with h click OK |
07:15 | Let me also
Rename the object c_1 as s which denotes slant height of cone. |
07:21 | Right click on object c_1 |
07:23 | click on Rename |
07:24 | Replace c_1 with s |
07:26 | Click OK |
07:28 | Let's find now surface area and volume of the cone, |
07:33 | We can use either the Insert text tool from the tool bar or we can use the input bar.
I will use the Input bar |
07:40 | Please find the special characters in the drop down list of the “Input bar” |
07:44 | Scroll down to find π |
07:48 | Type in the input bar
Area = (π a s + π a²) Surfacearea = open the bracket Select 'π' from the list space a space s plus select π from the list space a Select square from list close the bracket press enter |
08:15 | Surface Area of the cone is displayed in the Algebra view |
08:20 | Please note when we use the Input bar
answer appears in the Algebra view |
08:26 | Let's find Volume |
08:29 | Volume =(1/3 π a² h)
Volume =open bracket '1/3' space select 'π' from the list space a Select 'square' from list space h close the bracket Press enter |
08:50 | Volume of the cone is displayed here in the Algebra view |
08:55 | Lets now save the file. Click on file Save As.
I will type the file name as "Sphere-cone" |
09:08 | Click on Save. |
09:10 | with this we come to the end of this tutorial |
09:14 | Let us summarize |
09:18 | In this tutorial we have learnt to find |
09:20 | Area and perimeter of rhombus |
09:24 | Surface Area of sphere and cone |
09:27 | Volume of sphere and cone |
09:30 | We have also learnt to draw sphere and cone |
09:36 | As an assignment I would like you to find Surface area and volume of cylinder |
09:43 | Draw 2 ellipses of same sized one below the other |
09:47 | Connect edges of ellipses |
09:50 | Use center tool, find center of one ellipse |
09:54 | Join center and edge. |
09:56 | Rename object b as h and e as r |
10:01 | Surface area = 2 π r(r + h) |
10:07 | Volume = π r^2h |
10:13 | The output of the assignment should look like this. |
10:19 | Watch the video available at this URL |
10:23 | It summarises the Spoken Tutorial project |
10:26 | If you do not have good bandwidth, you can download and watch it |
10:31 | The Spoken Tutorial Project Team : |
10:33 | Conducts workshops using spoken tutorials |
10:36 | Gives certificates to those who pass an online test |
10:40 | For more details, please write to
contact@spoken-tutorial.org |
10:48 | Spoken Tutorial Project is a part of the Talk to a Teacher project |
10:52 | It is supported by the National Mission on Education through ICT, MHRD, Government of India |
10:59 | More information on this Mission is available at this link. |
11:06 | This is Madhuri Ganapathi from IIT Bombay signing off.
Thanks for joining |