Difference between revisions of "Sum of the interior angles of a quadrilateral"

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* What is the measure of the sum of angles in each quadrilateral? So what is the measure of all the angles of the quadrilateral?
 
* What is the measure of the sum of angles in each quadrilateral? So what is the measure of all the angles of the quadrilateral?
 
* Make different quadrilaterals. Divide it into two triangles, measure the angles of the two triangles, check their sum.
 
* Make different quadrilaterals. Divide it into two triangles, measure the angles of the two triangles, check their sum.
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* Tabulate the angles of the two triangles  {| class="wikitable" |Observation | colspan="4" |Triangle1 | colspan="4" |Triangle2 |Sum of angles of two triangle Triangle1 + Triangle2 |- | |Angle 1 |Angle 2 | Angle 3 |Sum of angles |Angle 1 |Angle 2 | Angle 3 |Sum of angles | |- |Q1 | | | | | | | | | |- |Q2 | | | | | | | | | |- |Q3 | | | | | | | | | |}
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* Tabulate the angles of the two triangles 
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{| class="wikitable"
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|Observation
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| colspan="4" |Triangle1
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| colspan="4" |Triangle2
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|Sum of angles of two triangle
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|Angle 1
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|Angle 2
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Angle 3
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|Sum of angles
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|Angle 1
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|Angle 2
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Angle 3
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|Sum of angles
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|Q1
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|Q2
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|Q3
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'''Evaluation at the end of the activity'''
 
'''Evaluation at the end of the activity'''
 
* Is the sum of any quadrilateral 360<sup>o</sup>.
 
* Is the sum of any quadrilateral 360<sup>o</sup>.

Revision as of 06:11, 16 April 2019

Objectives

  1. To establish that sum of interior angles of any quadrilateral is 360o

Estimated Time

40 minutes

Prerequisites/Instructions, prior preparations, if any

Prior knowledge of point, lines, angles, intersecting lines, vertically opposite angles, properties of triangle

Materials/ Resources needed

Process (How to do the activity)

  • In the geogebra sketch for the quadrilateral measure the sides and angles at the vertices
  • Calculate the sum of these angles of the quadrilateral? Note your observations
  • {| class="wikitable" |Quadrilateral |Side1 |Side2 |Side3 |Side4 |Angle1 |Angle2 |Angle3 |Angle4 |Angle1+Angle 2+ Angle3 + Angle 4 |Whatdo you observe about their sum |- |Q1 | | | | | | | | | | |- |Q2 | | | | | | | | | | |- |Q3 | | | | | | | | | | |}
  • Draw any one diagonal. What do you notice? What is the quadrilateral divided into? How many triangles are formed?
  • What is the measure of the sum of angles in each quadrilateral? So what is the measure of all the angles of the quadrilateral?
  • Make different quadrilaterals. Divide it into two triangles, measure the angles of the two triangles, check their sum.
  • Tabulate the angles of the two triangles 
Observation Triangle1 Triangle2 Sum of angles of two triangle
Angle 1 Angle 2

Angle 3

Sum of angles Angle 1 Angle 2

Angle 3

Sum of angles
Q1
Q2
Q3

Evaluation at the end of the activity

  • Is the sum of any quadrilateral 360o.
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