Line of reflective symmetry 1/2
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Line of reflective symmetry 1/2
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Each pupil will receive 2 origami sheets.
Two colored markers are needed.
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Activity:
Fold one of your sheets in any way you choose.
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Activity:
Open your folded sheet and with a marker, color the line that you have as a result of your folding. -
It is suggested that the line will be marked using your measurement tool.
To learn how to make the measuring tool, see the lesson, ‘A Measuring Tool for Comparison of Lengths’.
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A discussion question:
Investigate your sheet that has been opened. Will the two polygon shapes on the sides of of your colored line exactly cover one another if you fold them on each other? -
In many cases the colored line will not be a line of symmetry and the pupils should not be discouraged.
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A discussion question:
When do the shapes exactly cover each other? Look at the folds of other pupils. -
It is not necessary to use the concept of “half” or “equal”. Only relate to the covering of each shape one with the other.
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A discussion question:
Is the folded line on your sheet a line of symmetry? Explain.
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Answer:
When the two shapes are reflected exactly on each other, then your sheet (a square) has reflective symmetry. The line is named a line of reflective symmetry.
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Activity:
The class is divided into two groups. One group whose shape has a line of reflective symmetry and the other group whose line on the shape is not a line of reflective symmetry. -
The class is divided into two groups. One group whose colored line on the sheet is a line of reflective symmetry and the other group showing a colored line which is not a line of reflective symmetry.
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Activity:
Glue your open sheet with the colored line on a poster separating the sheets into two groups. One with a line of reflective symmetry and the other without. Attach a statement to each group. -
This is a class .activity
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A question at the end of the lesson:
Look around your classroom. Can you find other lines of reflective symmetry?
- Lesson Aims
- To identify a line of reflective symmetry.
- To discover the properties of a reflective line of symmetry in a given shape.
- To find a line of symmetry in a given shape.
- Model Name
Line of reflective symmetry 1/2
- 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, Quadrilaterals C: Square & Rectangle, Line of reflective symmetry 1/2, Line of reflective symmetry 2/2, , Lines of symmetry in quadrilaterals, Translation of shapes
- Lesson content
- This lesson is the first lesson about the concept of reflective symmetry. There is no final model and its contents are preparation for the following lesson whose model is at the core of the topic of symmetry.
- Prior knowledge
Polygons.
- Grade curriculum
- Materials
1. The measuring tool.
2. Two sheets of origami paper 15 cm x 15 cm.
3. Two colored markers.
