Difference between revisions of "Elements of a triangle"

Latest revision as of 16:20, 15 April 2019

Elements of a triangle are the angles that are formed when three lines intersect and the segments that mark the triangle are sides.

Objectives

To understand the elements of a triangle

Estimated Time

40 minutes

Prerequisites/ Instructions, prior preparations, if any

Prior knowledge of point, lines, angles, parallel lines

Materials/ Resources needed

Digital : Computer, Geogebra application, projector.
Non digital : Worksheet and pencil,6-8 strings (preferably in different colours)
Geogebra files : “Elements of a triangle.ggb”

Process (How to do the activity)

Student groups can be formed, students in their group do the following activity individually.
Take the strings and place them in such a way as to make a closed figure.
What is the smallest number of strings with which you can form a closed figure?
What is this figure called?
Can you just draw the lines along the strings and see what you get?
When you drew, what did you draw? (Was it a line or was it an angle or was it a line segment?). It is a lime segment – how many line segments are there?
When two line segments joined, what is it called? (A vertex). How many vertices are there?
Is there any angle formed when you made this figure? How many angles were formed? How many angles lie within the closed figure?
Show a simple Geogebra file with triangles – Use this file to demonstrate that every triangle has the elements - vertices, sides and angles
How many triangles were formed? Were there any strings left over?
For each of the triangles trace the shape on the book and write down the elements of the triangle in the following format

Vertices	Sides	Angles
.
.
.

For each of the triangles observe (inspect visually) which is the longest side and which is the shortest side

Triangle name	Largest angle	Largest side	Smallest angle	Smallest side
.
.
.

Allow the students to explore if there is any connection between the two?
After the students see the Geogebra file, they can attempt an alternative worksheet like below

Side 1	Angle 1 (opposite angle)	! Side 2	Angle 2 (opposite angle)	! Side 3	Angle 3 (opposite angle)	! Largest side and angle ex-side1,angle1	! Smallest side and angle ex-side3,angle3
.
.
.

Evaluation at the end of the activity

Have the students been able to identify the elements in a triangle?
Have they been able to extrapolate any connection between the angle and side in a triangle?

@@ Line 1: / Line 1: @@
-===Name of the activity===
+Elements of a triangle are the angles that are formed when three lines intersect and the segments that mark the triangle are sides.
-Brief blurb describing what the activity.  If this has been borrowed from some external web site (for example, a non OER or OER site which had this idea and based on which the activity was developed)
 === Objectives ===
-To understand the elements of a triangle
+* To understand the elements of a triangle
-*
 ===Estimated Time===
+minutes
-=== Prerequisites/Instructions, prior preparations, if any ===
+=== Prerequisites/ Instructions, prior preparations, if any ===
 Prior knowledge of point, lines, angles, parallel lines
 ===Materials/ Resources needed===
-#Digital : Computer, geogebra application, projector.
+*Digital : Computer, Geogebra application, projector.
-#Non digital : Worksheet and pencil,6-8 strings (preferably in different colours)
+*Non digital : Worksheet and pencil,6-8 strings (preferably in different colours)
-#Geogebra files :  '''“[https://www.geogebra.org/m/bwsvgqqg#material/hyecxd9u Elements of a triangle.ggb]”'''
+*Geogebra files :  '''“[https://ggbm.at/hyecxd9u Elements of a triangle.ggb]”'''
 ===Process (How to do the activity)===
-#Students work individually but in their groups.
+*Student groups can be formed, students in their group do the following activity individually.
-#Take the strings and place them in such a way as to make a closed figure.
+*Take the strings and place them in such a way as to make a closed figure.
-#What is the smallest number of strings with which you can form a closed figure?
+*What is the smallest number of strings with which you can form a closed figure?
-#What is this figure called?
+*What is this figure called?
-#Can you just draw the lines along the strings and see what you get?
+*Can you just draw the lines along the strings and see what you get?
-#When you drew, what did you draw?  (Was it a line or was it an angle or was it a line segment?). It is a lime segment – how many line segments are there?
+*When you drew, what did you draw?  (Was it a line or was it an angle or was it a line segment?). It is a lime segment – how many line segments are there?
-#When two line segments joined, what is it called?  (A vertex). How many vertices are there?
+*When two line segments joined, what is it called?  (A vertex). How many vertices are there?
-#Is there any angle formed when you made this figure? How many angles were formed?
+*Is there any angle formed when you made this figure? How many angles were formed? How many angles lie within the closed figure?
-#Show a simple Geogebra file with triangles – Use this file to demonstrate that every triangle has the elements - vertices, sides and angles
+*Show a simple Geogebra file with triangles – Use this file to demonstrate that every triangle has the elements - vertices, sides and angles
-#How many triangles were formed?  Were there any strings left over?
+*How many triangles were formed?  Were there any strings left over?
-#For each of the triangles trace the shape on the book and write down the elements of the triangle in the following format
+*For each of the triangles trace the shape on the book and write down the elements of the triangle in the following format
 {| class="wikitable"
 |-
 !Vertices!!Sides!!Angles
 |-
-|||||
+|.
+||||
 |-
-|||||
+|.||||
 |-
-|||||
+|.
-|}12.For each of the triangles observe (inspect visually) which is the longest side and which is the shortest side
+||||
+|}
+* For each of the triangles observe (inspect visually) which is the longest side and which is the shortest side
 {| class="wikitable"
 !Triangle name
@@ Line 43: / Line 47: @@
 !Smallest side
 |-
+|.
 |
 |
-|'''Evaluation at the end of the activity'''
-Have the students been able to identify the elements in a triangle?
-Have they been able to extrapolate any connection between the angle and side in a triangle?
 |
 |
 |-
-|
+|.
 |
 |
@@ Line 57: / Line 59: @@
 |
 |-
+|.
 |
 |
 |
 |
-|
 |}
-. Allow the students to explore if there is any connection between the two?
+* Allow the students to explore if there is any connection between the two?
+* After the students see the Geogebra file, they can attempt an alternative worksheet like below
+{| class="wikitable"
+|-
+!Side 1!!Angle 1
+(opposite angle)
+!! Side 2!!Angle 2
+(opposite angle)
+!! Side 3!!Angle 3
+(opposite angle)
+!! Largest side and angle
+ex-side1,angle1
+!! Smallest side and angle
+ex-side3,angle3
+|-
+|.
+||||||||||||||
+|-
+|.
+||||||||||||||
+|-
+|.
+||||||||||||||
+|}
+'''Evaluation at the end of the activity'''
+*Have the students been able to identify the elements in a triangle?
+*Have they been able to extrapolate any connection between the angle and side in a triangle?
-. After the students see the Geogebra file, they can attempt an alternative worksheet like below
+[[Category:Triangles]]