Difference between revisions of "Interior and exterior angles in triangle"
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(Interior and exterior angles of a triangle) |
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=== Objectives === | === Objectives === | ||
− | + | *Identify all angles when a triangle is formed | |
− | + | *Understand the relation between various angles that are formed in a triangle. | |
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===Estimated Time=== | ===Estimated Time=== | ||
=== Prerequisites/Instructions, prior preparations, if any === | === Prerequisites/Instructions, prior preparations, if any === | ||
+ | Prior knowledge of point, lines, angles | ||
===Materials/ Resources needed=== | ===Materials/ Resources needed=== | ||
+ | *Digital : Computer, geogebra application, projector. | ||
+ | *Non digital : Worksheet and pencil. | ||
+ | *Geogebra files : '''“[https://www.geogebra.org/m/bwsvgqqg#material/q6fnttmn Angles of triangle.ggb]”''' | ||
===Process (How to do the activity)=== | ===Process (How to do the activity)=== | ||
− | + | *Ask students how many lines are there? They should be able to identify the points of intersection of the lines. How many points of intersection are formed? | |
− | + | *How many angles are formed at an intersecting point? How many angles in total at the three points of intersection?What is the total angle measure at each intersecting point? | |
− | + | *How many angles are inside the triangle and how many are outside the triangle | |
− | + | *Can you find an exterior angle that is equal to the interior angle of a triangle at each vertex?Why are they equal? | |
− | + | *Identify the exterior angles that are equal? Justify why they are equal. | |
− | + | *Establish that there are 2 angles which are exterior of the triangle that are equal and are formed when the sides of the triangle is extended at the vertex. | |
− | + | *Students to analyze the interior and exterior angle at each point to find a relation between the interior angle and one of the exterior angles at the vertex. Students should be able to recognize the linear pair formed by interior angle and exterior angle. | |
+ | *Vary the position of the lines to check if interior and exterior angles form a linear pair. | ||
− | + | * Note the measure of angles | |
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+ | '''Evaluation at the end of the activity''' | ||
+ | *Are students able to recognize interior and exterior angles in a triangle | ||
+ | *Have the students able to find a relation between the interior angle and exterior angle that are formed at each vertex? |
Revision as of 10:38, 12 April 2019
Objectives
- Identify all angles when a triangle is formed
- Understand the relation between various angles that are formed in a triangle.
Estimated Time
Prerequisites/Instructions, prior preparations, if any
Prior knowledge of point, lines, angles
Materials/ Resources needed
- Digital : Computer, geogebra application, projector.
- Non digital : Worksheet and pencil.
- Geogebra files : “Angles of triangle.ggb”
Process (How to do the activity)
- Ask students how many lines are there? They should be able to identify the points of intersection of the lines. How many points of intersection are formed?
- How many angles are formed at an intersecting point? How many angles in total at the three points of intersection?What is the total angle measure at each intersecting point?
- How many angles are inside the triangle and how many are outside the triangle
- Can you find an exterior angle that is equal to the interior angle of a triangle at each vertex?Why are they equal?
- Identify the exterior angles that are equal? Justify why they are equal.
- Establish that there are 2 angles which are exterior of the triangle that are equal and are formed when the sides of the triangle is extended at the vertex.
- Students to analyze the interior and exterior angle at each point to find a relation between the interior angle and one of the exterior angles at the vertex. Students should be able to recognize the linear pair formed by interior angle and exterior angle.
- Vary the position of the lines to check if interior and exterior angles form a linear pair.
- Note the measure of angles
Evaluation at the end of the activity
- Are students able to recognize interior and exterior angles in a triangle
- Have the students able to find a relation between the interior angle and exterior angle that are formed at each vertex?