Difference between revisions of "Formation of a triangle"

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Three lines intersect with each other in a plane to form a closed figure. Vertices are formed at the intersecting points and edges that mark the triangle are sides.  [[File:Triangle formation.png|thumb|600x600px|'''[https://ggbm.at/z4h42k8z Introduction to a triangle.ggb]''']]
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Three lines intersect with each other in a plane to form a closed figure. Vertices are formed at the intersecting points and edges that mark the triangle are sides.   
 
 
 
=== Objectives ===
 
=== Objectives ===
 
*Understand formation of triangles
 
*Understand formation of triangles
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*Non digital : Worksheet and pencil
 
*Non digital : Worksheet and pencil
 
*Geogebra files :  '''“[https://ggbm.at/z4h42k8z Introduction to a triangle.ggb]”'''
 
*Geogebra files :  '''“[https://ggbm.at/z4h42k8z Introduction to a triangle.ggb]”'''
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{{Geogebra|https://www.geogebra.org/m/prvUJHb5}}
  
 
===Process (How to do the activity)===
 
===Process (How to do the activity)===

Revision as of 05:30, 22 April 2019

Three lines intersect with each other in a plane to form a closed figure. Vertices are formed at the intersecting points and edges that mark the triangle are sides.

Objectives

  • Understand formation of triangles
  • Recognize elements of triangle
  • Introduce concepts of exterior angle.

Estimated Time

30 minutes

Prerequisites/Instructions, prior preparations, if any

Prior knowledge of point, lines, angles, parallel lines

Materials/ Resources needed


Download this geogebra file from this link.


Process (How to do the activity)

  • Use the geogebra file to illustrate. The questions below will are used to interact with the geogebra sketch.
  • How many lines are there? Are the lines meeting?
  • Are the two lines parallel? How can you say they are parallel or not?
  • How many angles are formed at the point of intersection?
  • What is the measure of the total angle at the point of intersection of two lines?
  • Of the four angles formed which of the angles are equal? What are they called?
  • Do the three intersecting lines enclose a space? How does it look? It is called a triangle.
  • What are the points of intersection of these three lines called?
  • The line segments forming the triangle are called sides.
  • How many angles are formed when three lines intersect with each other?
  • How many angles are enclosed by the triangle?

Evaluation at the end of the activity

  • Can there be a closed figure with less than three sides?
  • Can the vertices of the triangle be anywhere on a plane?
  • What will happen if the three vertices are collinear?