Triangles activity A
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Triangles activity A
Each pupil should choose 2 sheets of colored paper.
Use only sheets of origami paper that have the correct flexibility and texture.
Folding instructions: Fold one vertex to lie on top of the opposite vertex, on both sheets.
During the folding, it is suggested that the pupils first align the two vertices and then move their finger along the fold.
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.
Answer:
The triangle formed has 3 vertices and 3 sides.In all following activities the correct terms: vertices, sides, triangle should be used.
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.
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.
Folding instructions:
Fold vertex to vertex as shown, and open.
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.
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.
Answer: In this folded shape 2 smaller triangles and 2 larger triangles can be identified.
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.
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.
Folding instructions: Fold only one vertex as shown.
The teacher demonstrates with his/her sheet. If necessary, this is done several times.
Folding instructions:
Turn the shape over.
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.
A discussion question:
Can you identify triangles with 3 vertices and 3 sides? .Ask the pupils to show these trangles with their fingers.
Folding instructions:
Fold the vertex as shown.Each folding stage increases the confidence of the pupils.
Folding instructions:
Put your fingers inside the folded box in order to open it.
A sweet box!
Final activity: With your other triangle, add three additional folds as you wish. Open your sheet and color the triangles that can be seen.
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.
