Triangles activity B
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Triangles activity B
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Each pupil should choose 2 sheets of colored paper.
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Use only sheets of origami paper that have the correct flexibility and texture.
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Folding instructions: Fold one vertex to lie on top of the opposite vertex, on both sheets.
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During the folding, it is suggested that the pupils first align the two vertices and then move their finger along the fold.
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A discussion question:
Can the number of sides and vertices be counted? -
The pupils should choose one vertex as a starting point and then move a finger along each side until they return to the starting point. A change in direction counts as a new side.
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Answer:
The triangle formed has 3 vertices and 3 sides. -
In all following activities the correct terms: vertices, sides, triangle should be used.
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A ‘pair activity’ of decomposition and composition of shapes.
Compose a larger triangle with the four smaller triangles. -
In this activity only sides of equal length should be joined. The teacher should demonstrate this point.
The pupils should describe the number of sides and vertices of the larger triangle.
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Decomposition and composition:
Count the number of sides and vertices of the new triangle. -
In this activity only sides of equal length should be joined. The teacher should demonstrate this point.
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Folding instructions:
Fold vertex to vertex as shown, and open.
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Folding instructions:
Fold two vertices to the line of symmetry, as seen in the animation. -
As yet, the pupils are not familiar with the term ‘line of symmetry’. This line should be demonstrated by the teacher. Remember not to touch the pupils’ paper.
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A discussion question:
Can you find triangles with 3 vertices and three sides? -
The pupils should choose one vertex as a starting point and then move a finger along each side until they return to the starting point. A change of direction means a new side.
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Answer: In this folded shape 2 smaller triangles and 2 larger triangles can be identified.
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In the animation, 2 smaller and 2 larger triangles are shown. The pupils should choose one vertex in each triangle, identified as a starting point and then move a finger along each side until they return to the starting point. A change of direction means a new side.
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Folding instructions:
Turn over the shape. -
At each stage of folding, the teacher should demonstrate the folding to be done.
It is important to point out to the pupils the 3 stages of folding.
1.Listen to the instruction before touching your sheet.
2. Understand the instruction. 3. Perform the necessary folding.
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Folding instructions: Fold only one vertex as shown.
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The teacher demonstrates with his/her sheet. If necessary, this is done several times.
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Folding instructions:
Turn the shape over.
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Folding instructions:
Fold each marked side to the line of symmetry. -
As yet, the pupils are not familiar with the term ‘line of symmetry’. This line should be demonstrated by the teacher.
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A discussion question:
Can you identify triangles with 3 vertices and 3 sides? . -
Ask the pupils to show these trangles with their fingers.
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Folding instructions:
Fold the vertex as shown. -
Each folding stage increases the confidence of the pupils.
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Folding instructions:
Put your fingers inside the folded box in order to open it.
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A sweet box!
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Final activity: With your other triangle, add three additional folds as you wish. Open your sheet and color the triangles that can be seen.
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This activity allows the pupils to identify various forms of triangle.
- Lesson Aims
.The pupils will identify and investigate triangles according to properties
- Name of Model
A sweets box.
- The Lesson structure
Triangles activity A, ,Triangles activity B, Polygon activity A, Polygon activity A , Polygon activities B 1/2 , Polygon activities B 2/2 , Polygon activity C , A measuring tool for comparison of lengths , Quadrilaterals A , Quadrilaterals B: Square & Rectangle – same and different, Line of reflective symmetry 1/2, Line of reflective symmetry 2/2, Quadrilaterals C: Square & Rectangle , Lines of symmetry in quadrilaterals, Translation of shapes
- Lesson content
In this lesson, the pupils will investigate the properties of triangles: three sides and three vertices, identifying them in different forms as a result of folding activities. At the end of the lesson they see the folding leading to a surprise model. During the activities they are learning new concepts and revising those previously learnt.
- Prior Knowledge
- Stages in the curriculum
- Materials
Origami paper: 15 cm x 15 cm.
